| 113. | B Garlyyev, S Xue, J Fichtner, A S Bandarenka, C Andronescu Prospects of Value-Added Chemicals and Hydrogen via Electrolysis Journal Article Chemsuschem, 13 (10), pp. 2513-2521, 2020, ISSN: 1864-5631. Abstract | Links | Tags: Foundry Inorganic, Solid-Liquid @article{, title = {Prospects of Value-Added Chemicals and Hydrogen via Electrolysis}, author = {B Garlyyev and S Xue and J Fichtner and A S Bandarenka and C Andronescu}, url = {<Go to ISI>://WOS:000520259100001}, doi = {10.1002/cssc.202000339}, issn = {1864-5631}, year = {2020}, date = {2020-05-22}, journal = {Chemsuschem}, volume = {13}, number = {10}, pages = {2513-2521}, abstract = {Cost is a major drawback that limits the industrial-scale hydrogen production through water electrolysis. The overall cost of this technology can be decreased by coupling the electrosynthesis of value-added chemicals at the anode side with electrolytic hydrogen generation at the cathode. This Minireview provides a directory of anodic oxidation reactions that can be combined with cathodic hydrogen generation. The important parameters for selecting the anodic reactions, such as choice of catalyst material and its selectivity towards specific products are elaborated in detail. Furthermore, various novel electrolysis cell architectures for effortless separation of value-added products from hydrogen gas are described.}, keywords = {Foundry Inorganic, Solid-Liquid}, pubstate = {published}, tppubtype = {article} } Cost is a major drawback that limits the industrial-scale hydrogen production through water electrolysis. The overall cost of this technology can be decreased by coupling the electrosynthesis of value-added chemicals at the anode side with electrolytic hydrogen generation at the cathode. This Minireview provides a directory of anodic oxidation reactions that can be combined with cathodic hydrogen generation. The important parameters for selecting the anodic reactions, such as choice of catalyst material and its selectivity towards specific products are elaborated in detail. Furthermore, various novel electrolysis cell architectures for effortless separation of value-added products from hydrogen gas are described. |
| 112. | J W Borchert, U Zschieschang, F Letzkus, M Giorgio, R T Weitz, M Caironi, J N Burghartz, S Ludwigs, H Klauk Flexible low-voltage high-frequency organic thin-film transistors Journal Article Science Advances, 6 (21), 2020, ISSN: 2375-2548. Abstract | Links | Tags: Foundry Organic, Molecularly Functionalized @article{, title = {Flexible low-voltage high-frequency organic thin-film transistors}, author = {J W Borchert and U Zschieschang and F Letzkus and M Giorgio and R T Weitz and M Caironi and J N Burghartz and S Ludwigs and H Klauk}, url = {<Go to ISI>://WOS:000537235300049}, doi = {10.1126/sciadv.aaz5156}, issn = {2375-2548}, year = {2020}, date = {2020-05-20}, journal = {Science Advances}, volume = {6}, number = {21}, abstract = {The primary driver for the development of organic thin-film transistors (TFTs) over the past few decades has been the prospect of electronics applications on unconventional substrates requiring low-temperature processing. A key requirement for many such applications is high-frequency switching or amplification at the low operating voltages provided by lithium-ion batteries (similar to 3 V). To date, however, most organic-TFT technologies show limited dynamic performance unless high operating voltages are applied to mitigate high contact resistances and large parasitic capacitances. Here, we present flexible low-voltage organic TFTs with record static and dynamic performance, including contact resistance as small as 10 Omega.cm, on/off current ratios as large as 10(10), subthreshold swing as small as 59 mV/decade, signal delays below 80 ns in inverters and ring oscillators, and transit frequencies as high as 21 MHz, all while using an inverted coplanar TFT structure that can be readily adapted to industry-standard lithographic techniques.}, keywords = {Foundry Organic, Molecularly Functionalized}, pubstate = {published}, tppubtype = {article} } The primary driver for the development of organic thin-film transistors (TFTs) over the past few decades has been the prospect of electronics applications on unconventional substrates requiring low-temperature processing. A key requirement for many such applications is high-frequency switching or amplification at the low operating voltages provided by lithium-ion batteries (similar to 3 V). To date, however, most organic-TFT technologies show limited dynamic performance unless high operating voltages are applied to mitigate high contact resistances and large parasitic capacitances. Here, we present flexible low-voltage organic TFTs with record static and dynamic performance, including contact resistance as small as 10 Omega.cm, on/off current ratios as large as 10(10), subthreshold swing as small as 59 mV/decade, signal delays below 80 ns in inverters and ring oscillators, and transit frequencies as high as 21 MHz, all while using an inverted coplanar TFT structure that can be readily adapted to industry-standard lithographic techniques. |
| 111. | T Deilmann, M Rohlfing, U Wurstbauer Light-matter interaction in van der Waals hetero-structures Journal Article Journal of Physics-Condensed Matter, 32 (33), 2020, ISSN: 0953-8984. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Light-matter interaction in van der Waals hetero-structures}, author = {T Deilmann and M Rohlfing and U Wurstbauer}, url = {<Go to ISI>://WOS:000536663700001}, doi = {10.1088/1361-648X/ab8661}, issn = {0953-8984}, year = {2020}, date = {2020-05-15}, journal = {Journal of Physics-Condensed Matter}, volume = {32}, number = {33}, abstract = {Even if individual two-dimensional materials own various interesting and unexpected properties, the stacking of such layers leads to van der Waals solids which unite the characteristics of two dimensions with novel features originating from the interlayer interactions. In this topical review, we cover fabrication and characterization of van der Waals hetero-structures with a focus on hetero-bilayers made of monolayers of semiconducting transition metal dichalcogenides. Experimental and theoretical techniques to investigate those hetero-bilayers are introduced. Most recent findings focusing on different transition metal dichalcogenides hetero-structures are presented and possible optical transitions between different valleys, appearance of moire patterns and signatures of moire excitons are discussed. The fascinating and fast growing research on van der Waals hetero-bilayers provide promising insights required for their application as emerging quantum-nano materials.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Even if individual two-dimensional materials own various interesting and unexpected properties, the stacking of such layers leads to van der Waals solids which unite the characteristics of two dimensions with novel features originating from the interlayer interactions. In this topical review, we cover fabrication and characterization of van der Waals hetero-structures with a focus on hetero-bilayers made of monolayers of semiconducting transition metal dichalcogenides. Experimental and theoretical techniques to investigate those hetero-bilayers are introduced. Most recent findings focusing on different transition metal dichalcogenides hetero-structures are presented and possible optical transitions between different valleys, appearance of moire patterns and signatures of moire excitons are discussed. The fascinating and fast growing research on van der Waals hetero-bilayers provide promising insights required for their application as emerging quantum-nano materials. |
| 110. | S Xue, B Garlyyev, A Auer, J Kunze-Liebhauser, A S Bandarenka How the Nature of the Alkali Metal Cations Influences the Double-Layer Capacitance of Cu, Au, and Pt Single-Crystal Electrodes Journal Article Journal of Physical Chemistry C, 124 (23), pp. 12442-12447, 2020, ISSN: 1932-7447. Abstract | Links | Tags: Foundry Inorganic, Solid-Liquid @article{, title = {How the Nature of the Alkali Metal Cations Influences the Double-Layer Capacitance of Cu, Au, and Pt Single-Crystal Electrodes}, author = {S Xue and B Garlyyev and A Auer and J Kunze-Liebhauser and A S Bandarenka}, url = {<Go to ISI>://WOS:000541745800029}, doi = {10.1021/acs.jpcc.0c01715}, issn = {1932-7447}, year = {2020}, date = {2020-05-09}, journal = {Journal of Physical Chemistry C}, volume = {124}, number = {23}, pages = {12442-12447}, abstract = {In this work, we have investigated the influence of alkali metal cations on the electrical double-layer (EDL) properties for various metal electrodes. Using electrochemical impedance spectroscopy, we demonstrate that those cations significantly affect the EDL capacitance in the case of single-crystalline Cu(111), Cu(100), Au(111), Pt(111), stepped Pt(775), and kinked Pt(12 10 5) electrodes in 0.05 M MeClO4 (Me+ = Li+, Na+, K+, Rb+, and Cs+) electrolytes. For all the electrodes, the capacitance always linearly increases with decreasing hydration energy of Me+ in the following order: Li+ < Na+ < K+ < Rb+ < Cs+. Moreover, we estimate the effective concentrations of the alkali metal cations near the electrode surfaces by correlating the capacitances with the relative permittivity. For all the electrodes, the concentrations near the electrode surface were calculated to be similar to 60 to 80 times higher than in the bulk solutions.}, keywords = {Foundry Inorganic, Solid-Liquid}, pubstate = {published}, tppubtype = {article} } In this work, we have investigated the influence of alkali metal cations on the electrical double-layer (EDL) properties for various metal electrodes. Using electrochemical impedance spectroscopy, we demonstrate that those cations significantly affect the EDL capacitance in the case of single-crystalline Cu(111), Cu(100), Au(111), Pt(111), stepped Pt(775), and kinked Pt(12 10 5) electrodes in 0.05 M MeClO4 (Me+ = Li+, Na+, K+, Rb+, and Cs+) electrolytes. For all the electrodes, the capacitance always linearly increases with decreasing hydration energy of Me+ in the following order: Li+ < Na+ < K+ < Rb+ < Cs+. Moreover, we estimate the effective concentrations of the alkali metal cations near the electrode surfaces by correlating the capacitances with the relative permittivity. For all the electrodes, the concentrations near the electrode surface were calculated to be similar to 60 to 80 times higher than in the bulk solutions. |
| 109. | A Singldinger, M Gramlich, C Gruber, C Lampe, A S Urban Nonradiative Energy Transfer between Thickness-Controlled Halide Perovskite Nanoplatelets Journal Article Acs Energy Letters, 5 (5), pp. 1380-1385, 2020, ISSN: 2380-8195. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Nonradiative Energy Transfer between Thickness-Controlled Halide Perovskite Nanoplatelets}, author = {A Singldinger and M Gramlich and C Gruber and C Lampe and A S Urban}, url = {<Go to ISI>://WOS:000535176100006}, doi = {10.1021/acsenergylett.0c00471}, issn = {2380-8195}, year = {2020}, date = {2020-05-08}, journal = {Acs Energy Letters}, volume = {5}, number = {5}, pages = {1380-1385}, abstract = {Despite showing great promise for optoelectronics, the commercialization of halide perovskite nanostructure-based devices is hampered by inefficient electrical excitation and strong exciton binding energies. While transport of excitons in an energy-tailored system via Forster resonance energy transfer (FRET) could be an efficient alternative, halide ion migration makes the realization of cascaded structures difficult. Here, we show how these could be obtained by exploiting the pronounced quantum confinement effect in two-dimensional CsPbBr3-based nanoplatelets (NPls). In thin films of NPls of two predetermined thicknesses, we observe an enhanced acceptor photoluminescence (PL) emission and a decreased donor PL lifetime. This indicates a FRET-mediated process, benefitted by the structural parameters of the NPls. We determine corresponding transfer rates up to k(FRET) = 0.99 ns(-1) and efficiencies of nearly eta(FRET) = 70%. We also show FRET to occur between perovskite NPls of other thicknesses. Consequently, this strategy could lead to tailored energy cascade nanostructures for improved optoelectronic devices.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Despite showing great promise for optoelectronics, the commercialization of halide perovskite nanostructure-based devices is hampered by inefficient electrical excitation and strong exciton binding energies. While transport of excitons in an energy-tailored system via Forster resonance energy transfer (FRET) could be an efficient alternative, halide ion migration makes the realization of cascaded structures difficult. Here, we show how these could be obtained by exploiting the pronounced quantum confinement effect in two-dimensional CsPbBr3-based nanoplatelets (NPls). In thin films of NPls of two predetermined thicknesses, we observe an enhanced acceptor photoluminescence (PL) emission and a decreased donor PL lifetime. This indicates a FRET-mediated process, benefitted by the structural parameters of the NPls. We determine corresponding transfer rates up to k(FRET) = 0.99 ns(-1) and efficiencies of nearly eta(FRET) = 70%. We also show FRET to occur between perovskite NPls of other thicknesses. Consequently, this strategy could lead to tailored energy cascade nanostructures for improved optoelectronic devices. |
| 108. | P Alexa, J M Lombardi, P Abufager, H F Busnengo, D Grumelli, V S Vyas, F Haase, B V Lotsch, R Gutzler, K Kern Enhancing Hydrogen Evolution Activity of Au(111) in Alkaline Media through Molecular Engineering of a 2D Polymer Journal Article Angewandte Chemie International Edition, n/a (n/a), 2020, ISSN: 1433-7851. Abstract | Links | Tags: Solid-Liquid @article{, title = {Enhancing Hydrogen Evolution Activity of Au(111) in Alkaline Media through Molecular Engineering of a 2D Polymer}, author = {P Alexa and J M Lombardi and P Abufager and H F Busnengo and D Grumelli and V S Vyas and F Haase and B V Lotsch and R Gutzler and K Kern}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201915855}, doi = {10.1002/anie.201915855}, issn = {1433-7851}, year = {2020}, date = {2020-05-05}, journal = {Angewandte Chemie International Edition}, volume = {n/a}, number = {n/a}, abstract = {Abstract The electrochemical splitting of water holds promise for the storage of energy produced intermittently by renewable energy sources. The evolution of hydrogen currently relies on the use of platinum as a catalyst\textemdashwhich is scarce and expensive\textemdashand ongoing research is focused towards finding cheaper alternatives. In this context, 2D polymers grown as single layers on surfaces have emerged as porous materials with tunable chemical and electronic structures that can be used for improving the catalytic activity of metal surfaces. Here, we use designed organic molecules to fabricate covalent 2D architectures by an Ullmann-type coupling reaction on Au(111). The polymer-patterned gold electrode exhibits a hydrogen evolution reaction activity up to three times higher than that of bare gold. Through rational design of the polymer on the molecular level we engineered hydrogen evolution activity by an approach that can be easily extended to other electrocatalytic reactions.}, keywords = {Solid-Liquid}, pubstate = {published}, tppubtype = {article} } Abstract The electrochemical splitting of water holds promise for the storage of energy produced intermittently by renewable energy sources. The evolution of hydrogen currently relies on the use of platinum as a catalyst—which is scarce and expensive—and ongoing research is focused towards finding cheaper alternatives. In this context, 2D polymers grown as single layers on surfaces have emerged as porous materials with tunable chemical and electronic structures that can be used for improving the catalytic activity of metal surfaces. Here, we use designed organic molecules to fabricate covalent 2D architectures by an Ullmann-type coupling reaction on Au(111). The polymer-patterned gold electrode exhibits a hydrogen evolution reaction activity up to three times higher than that of bare gold. Through rational design of the polymer on the molecular level we engineered hydrogen evolution activity by an approach that can be easily extended to other electrocatalytic reactions. |
| 107. | W Chen, H D Tang, N Li, M A Scheel, Y Xie, D P Li, V Korstgens, M Schwartzkopf, S V Roth, K Wang, X W Sun, P Muller-Buschbaum Colloidal PbS quantum dot stacking kinetics during deposition via printing Journal Article Nanoscale Horizons, 5 (5), pp. 880-885, 2020, ISSN: 2055-6756. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Colloidal PbS quantum dot stacking kinetics during deposition via printing}, author = {W Chen and H D Tang and N Li and M A Scheel and Y Xie and D P Li and V Korstgens and M Schwartzkopf and S V Roth and K Wang and X W Sun and P Muller-Buschbaum}, url = {<Go to ISI>://WOS:000531354100007}, doi = {10.1039/d0nh00008f}, issn = {2055-6756}, year = {2020}, date = {2020-05-01}, journal = {Nanoscale Horizons}, volume = {5}, number = {5}, pages = {880-885}, abstract = {Colloidal PbS quantum dots (QDs) are attractive for solution-processed thin-film optoelectronic applications. In particular, directly achieving QD thin-films by printing is a very promising method for low-cost and large-scale fabrication. The kinetics of QD particles during the deposition process play an important role in the QD film quality and their respective optoelectronic performance. In this work, the particle self-organization behavior of small-sized QDs with an average diameter of 2.88 +/- 0.36 nm is investigated for the first time in situ during printing by grazing-incidence small-angle X-ray scattering (GISAXS). The time-dependent changes in peak intensities suggest that the structure formation and phase transition of QD films happen within 30 seconds. The stacking of QDs is initialized by a templating effect, and a face-centered cubic (FCC) film forms in which a superlattice distortion is also found. A body-centered cubic nested FCC stacking is the final QD assembly layout. The small size of the inorganic QDs and the ligand collapse during the solvent evaporation can well explain this stacking behavior. These results provide important fundamental understanding of structure formation of small-sized QD based films prepared via large-scale deposition with printing with a slot die coater.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Colloidal PbS quantum dots (QDs) are attractive for solution-processed thin-film optoelectronic applications. In particular, directly achieving QD thin-films by printing is a very promising method for low-cost and large-scale fabrication. The kinetics of QD particles during the deposition process play an important role in the QD film quality and their respective optoelectronic performance. In this work, the particle self-organization behavior of small-sized QDs with an average diameter of 2.88 +/- 0.36 nm is investigated for the first time in situ during printing by grazing-incidence small-angle X-ray scattering (GISAXS). The time-dependent changes in peak intensities suggest that the structure formation and phase transition of QD films happen within 30 seconds. The stacking of QDs is initialized by a templating effect, and a face-centered cubic (FCC) film forms in which a superlattice distortion is also found. A body-centered cubic nested FCC stacking is the final QD assembly layout. The small size of the inorganic QDs and the ligand collapse during the solvent evaporation can well explain this stacking behavior. These results provide important fundamental understanding of structure formation of small-sized QD based films prepared via large-scale deposition with printing with a slot die coater. |
| 106. | Q He, A T S Freiberg, M U M Patel, S Qian, H A Gasteiger Operando Identification of Liquid Intermediates in Lithium-Sulfur Batteries via Transmission UV-vis Spectroscopy Journal Article Journal of the Electrochemical Society, 167 (8), 2020, ISSN: 0013-4651. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Operando Identification of Liquid Intermediates in Lithium-Sulfur Batteries via Transmission UV-vis Spectroscopy}, author = {Q He and A T S Freiberg and M U M Patel and S Qian and H A Gasteiger}, url = {<Go to ISI>://WOS:000527393000001}, doi = {10.1149/1945-7111/ab8645}, issn = {0013-4651}, year = {2020}, date = {2020-04-21}, journal = {Journal of the Electrochemical Society}, volume = {167}, number = {8}, abstract = {Lithium-sulfur (Li-S) batteries are facing various challenges with regards to performance and durability, and further improvements require a better understanding of the fundamental working mechanisms, including an identification of the reaction intermediates in an operating Li-S battery. In this study, we present an operando transmission UV-vis spectro-electrochemical cell design that employs a conventional sulfur/carbon composite electrode, propose a comprehensive peak assignment for polysulfides in DOL: DME-based electrolyte, and finally identify the liquid intermediates in the discharging process of an operating Li-S cell. Here, we propose for the first time a meta-stable polysulfide species (S-3(2-)) that is present at substantial concentrations during the 2nd discharge plateau in a Li-S battery. We identify the S-3(2-) species that are the reduction product of S-4(2-), as deducted from the analysis of the obtained operando UV-vis spectra along with the transferred charge, and confirmed by rotating ring disk electrode measurements for the reduction of a solution with a nominal Li2S4 stoichiometry. Furthermore, our operando results provide insight into the potential-dependent stability of different S-species and the rate-limiting (electro)chemical steps during discharging. Finally, we propose a viable reaction pathway of how S-8 is electrochemically reduced to Li2S2/Li2S based on our operando results as well as that reported in the literature. (c) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Lithium-sulfur (Li-S) batteries are facing various challenges with regards to performance and durability, and further improvements require a better understanding of the fundamental working mechanisms, including an identification of the reaction intermediates in an operating Li-S battery. In this study, we present an operando transmission UV-vis spectro-electrochemical cell design that employs a conventional sulfur/carbon composite electrode, propose a comprehensive peak assignment for polysulfides in DOL: DME-based electrolyte, and finally identify the liquid intermediates in the discharging process of an operating Li-S cell. Here, we propose for the first time a meta-stable polysulfide species (S-3(2-)) that is present at substantial concentrations during the 2nd discharge plateau in a Li-S battery. We identify the S-3(2-) species that are the reduction product of S-4(2-), as deducted from the analysis of the obtained operando UV-vis spectra along with the transferred charge, and confirmed by rotating ring disk electrode measurements for the reduction of a solution with a nominal Li2S4 stoichiometry. Furthermore, our operando results provide insight into the potential-dependent stability of different S-species and the rate-limiting (electro)chemical steps during discharging. Finally, we propose a viable reaction pathway of how S-8 is electrochemically reduced to Li2S2/Li2S based on our operando results as well as that reported in the literature. (c) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. |
| 105. | T L Maier, M Golibrzuch, S Mendisch, W Schindler, M Becherer, K Krischer Lateral silicon oxide/gold interfaces enhance the rate of electrochemical hydrogen evolution reaction in alkaline media Journal Article Journal of Chemical Physics, 152 (15), 2020, ISSN: 0021-9606. Abstract | Links | Tags: Foundry Inorganic, Solid-Liquid @article{, title = {Lateral silicon oxide/gold interfaces enhance the rate of electrochemical hydrogen evolution reaction in alkaline media}, author = {T L Maier and M Golibrzuch and S Mendisch and W Schindler and M Becherer and K Krischer}, url = {<Go to ISI>://WOS:000529243500002}, doi = {10.1063/5.0003295}, issn = {0021-9606}, year = {2020}, date = {2020-04-21}, journal = {Journal of Chemical Physics}, volume = {152}, number = {15}, abstract = {The production of solar hydrogen with a silicon based water splitting device is a promising future technology, and silicon-based metal-insulator-semiconductor (MIS) electrodes have been proposed as suitable architectures for efficient photocathodes based on the electronic properties of the MIS structures and the catalytic properties of the metals. In this paper, we demonstrate that the interfaces between the metal and oxide of laterally patterned MIS electrodes may strongly enhance the catalytic activity of the electrode compared to bulk metal surfaces. The employed electrodes consist of well-defined, large-area arrays of gold structures of various mesoscopic sizes embedded in a silicon oxide support on silicon. We demonstrate that the activity of these electrodes for hydrogen evolution reaction (HER) increases with an increase in gold/silicon oxide boundary length in both acidic and alkaline media, although the enhancement of the HER rate in alkaline electrolytes is considerably larger than in acidic electrolytes. Electrodes with the largest interfacial length of gold/silicon oxide exhibited a 10-times larger HER rate in alkaline electrolytes than those with the smallest interfacial length. The data suggest that at the metal/silicon oxide boundaries, alkaline HER is enhanced through a bifunctional mechanism, which we tentatively relate to the laterally structured electrode geometry and to positive charges present in silicon oxide: Both properties change locally the interfacial electric field at the gold/silicon oxide boundary, which, in turn, facilitates a faster transport of hydroxide ions away from the electrode/electrolyte interface in alkaline solution. This mechanism boosts the alkaline HER activity of p-type silicon based photoelectrodes close to their HER activity in acidic electrolytes.}, keywords = {Foundry Inorganic, Solid-Liquid}, pubstate = {published}, tppubtype = {article} } The production of solar hydrogen with a silicon based water splitting device is a promising future technology, and silicon-based metal-insulator-semiconductor (MIS) electrodes have been proposed as suitable architectures for efficient photocathodes based on the electronic properties of the MIS structures and the catalytic properties of the metals. In this paper, we demonstrate that the interfaces between the metal and oxide of laterally patterned MIS electrodes may strongly enhance the catalytic activity of the electrode compared to bulk metal surfaces. The employed electrodes consist of well-defined, large-area arrays of gold structures of various mesoscopic sizes embedded in a silicon oxide support on silicon. We demonstrate that the activity of these electrodes for hydrogen evolution reaction (HER) increases with an increase in gold/silicon oxide boundary length in both acidic and alkaline media, although the enhancement of the HER rate in alkaline electrolytes is considerably larger than in acidic electrolytes. Electrodes with the largest interfacial length of gold/silicon oxide exhibited a 10-times larger HER rate in alkaline electrolytes than those with the smallest interfacial length. The data suggest that at the metal/silicon oxide boundaries, alkaline HER is enhanced through a bifunctional mechanism, which we tentatively relate to the laterally structured electrode geometry and to positive charges present in silicon oxide: Both properties change locally the interfacial electric field at the gold/silicon oxide boundary, which, in turn, facilitates a faster transport of hydroxide ions away from the electrode/electrolyte interface in alkaline solution. This mechanism boosts the alkaline HER activity of p-type silicon based photoelectrodes close to their HER activity in acidic electrolytes. |
| 104. | S Paul, E Bladt, A F Richter, M Doblinger, Y Tong, H Huang, A Dey, S Bals, T Debnath, L Polavarapu, J Feldmann Manganese-Doping-Induced Quantum Confinement within Host Perovskite Nanocrystals through Ruddlesden-Popper Defects Journal Article Angewandte Chemie-International Edition, 59 (17), pp. 6794-6799, 2020, ISSN: 1433-7851. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Manganese-Doping-Induced Quantum Confinement within Host Perovskite Nanocrystals through Ruddlesden-Popper Defects}, author = {S Paul and E Bladt and A F Richter and M Doblinger and Y Tong and H Huang and A Dey and S Bals and T Debnath and L Polavarapu and J Feldmann}, url = {<Go to ISI>://WOS:000525279800024}, doi = {10.1002/anie.201914473}, issn = {1433-7851}, year = {2020}, date = {2020-04-20}, journal = {Angewandte Chemie-International Edition}, volume = {59}, number = {17}, pages = {6794-6799}, abstract = {The concept of doping Mn2+ ions into II-VI semiconductor nanocrystals (NCs) was recently extended to perovskite NCs. To date, most studies on Mn2+ doped NCs focus on enhancing the emission related to the Mn2+ dopant via an energy transfer mechanism. Herein, we found that the doping of Mn2+ ions into CsPbCl3 NCs not only results in a Mn2+-related orange emission, but also strongly influences the excitonic properties of the host NCs. We observe for the first time that Mn2+ doping leads to the formation of RuddlesdenPopper (R.P.) defects and thus induces quantum confinement within the host NCs. We find that a slight doping with Mn2+ ions improves the size distribution of the NCs, which results in a prominent excitonic peak. However, with increasing the Mn2+ concentration, the number of R.P. planes increases leading to smaller single-crystal domains. The thus enhanced confinement and crystal inhomogeneity cause a gradual blue shift and broadening of the excitonic transition, respectively.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } The concept of doping Mn2+ ions into II-VI semiconductor nanocrystals (NCs) was recently extended to perovskite NCs. To date, most studies on Mn2+ doped NCs focus on enhancing the emission related to the Mn2+ dopant via an energy transfer mechanism. Herein, we found that the doping of Mn2+ ions into CsPbCl3 NCs not only results in a Mn2+-related orange emission, but also strongly influences the excitonic properties of the host NCs. We observe for the first time that Mn2+ doping leads to the formation of RuddlesdenPopper (R.P.) defects and thus induces quantum confinement within the host NCs. We find that a slight doping with Mn2+ ions improves the size distribution of the NCs, which results in a prominent excitonic peak. However, with increasing the Mn2+ concentration, the number of R.P. planes increases leading to smaller single-crystal domains. The thus enhanced confinement and crystal inhomogeneity cause a gradual blue shift and broadening of the excitonic transition, respectively. |
| 103. | S S Matikonda, G Hammersley, N Kumari, L Grabenhorst, V Glembockyte, P Tinnefeld, J Ivanic, M Levitus, M J Schnermann Impact of Cyanine Conformational Restraint in the Near-Infrared Range Journal Article The Journal of Organic Chemistry, 2020, ISSN: 0022-3263. Links | Tags: Foundry Organic, Molecularly Functionalized @article{, title = {Impact of Cyanine Conformational Restraint in the Near-Infrared Range}, author = {S S Matikonda and G Hammersley and N Kumari and L Grabenhorst and V Glembockyte and P Tinnefeld and J Ivanic and M Levitus and M J Schnermann}, url = {https://doi.org/10.1021/acs.joc.0c00236}, doi = {10.1021/acs.joc.0c00236}, issn = {0022-3263}, year = {2020}, date = {2020-04-10}, journal = {The Journal of Organic Chemistry}, keywords = {Foundry Organic, Molecularly Functionalized}, pubstate = {published}, tppubtype = {article} } |
| 102. | K Trofymchuk, V Glembockyte, L Grabenhorst, F Steiner, C Vietz, C Close, M Pfeiffer, L Richter, M L Schütte, F Selbach, R Yaadav, J Zähringer, Q Wei, A Ozcan, B Lalkens, G P Acuna, P Tinnefeld Addressable Nanoantennas with Cleared Hotspots for Single-Molecule Detection on a Portable Smartphone Microscope Journal Article bioRxiv, pp. 2020.04.09.032037, 2020. Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized @article{, title = {Addressable Nanoantennas with Cleared Hotspots for Single-Molecule Detection on a Portable Smartphone Microscope}, author = {K Trofymchuk and V Glembockyte and L Grabenhorst and F Steiner and C Vietz and C Close and M Pfeiffer and L Richter and M L Sch\"{u}tte and F Selbach and R Yaadav and J Z\"{a}hringer and Q Wei and A Ozcan and B Lalkens and G P Acuna and P Tinnefeld}, url = {http://biorxiv.org/content/early/2020/04/09/2020.04.09.032037.abstract}, doi = {10.1101/2020.04.09.032037}, year = {2020}, date = {2020-04-09}, journal = {bioRxiv}, pages = {2020.04.09.032037}, abstract = {The advent of highly sensitive photodetectors1,2 and the development of photostabilization strategies3 made detecting the fluorescence of a single molecule a routine task in many labs around the world. However, to this day, this process requires cost-intensive optical instruments due to the truly nanoscopic signal of a single emitter. Simplifying single-molecule detection would enable many exciting applications, e.g. in point-of-care diagnostic settings, where costly equipment would be prohibitive.4 Here, we introduce addressable NanoAntennas with Cleared HOtSpots (NACHOS) that are scaffolded by DNA origami nanostructures and can be specifically tailored for the incorporation of bioassays. Single emitters placed in the NACHOS emit up to 461-fold brighter enabling their detection with a customary smartphone camera and an 8-US-dollar objective lens. To prove the applicability of our system, we built a portable, battery-powered smartphone microscope and successfully carried out an exemplary single-molecule detection assay for DNA specific to antibiotic-resistant Klebsiella pneumonia "on the road “.Competing Interest StatementPT and GPA are inventors on a patent of the described Bottom-up method for fluorescence enhancement in molecular assays, EP1260316.1, 2012, US20130252825 A1.}, keywords = {Foundry Organic, Molecularly-Functionalized}, pubstate = {published}, tppubtype = {article} } The advent of highly sensitive photodetectors1,2 and the development of photostabilization strategies3 made detecting the fluorescence of a single molecule a routine task in many labs around the world. However, to this day, this process requires cost-intensive optical instruments due to the truly nanoscopic signal of a single emitter. Simplifying single-molecule detection would enable many exciting applications, e.g. in point-of-care diagnostic settings, where costly equipment would be prohibitive.4 Here, we introduce addressable NanoAntennas with Cleared HOtSpots (NACHOS) that are scaffolded by DNA origami nanostructures and can be specifically tailored for the incorporation of bioassays. Single emitters placed in the NACHOS emit up to 461-fold brighter enabling their detection with a customary smartphone camera and an 8-US-dollar objective lens. To prove the applicability of our system, we built a portable, battery-powered smartphone microscope and successfully carried out an exemplary single-molecule detection assay for DNA specific to antibiotic-resistant Klebsiella pneumonia "on the road “.Competing Interest StatementPT and GPA are inventors on a patent of the described Bottom-up method for fluorescence enhancement in molecular assays, EP1260316.1, 2012, US20130252825 A1. |
| 101. | M Kraut, E Sirotti, F Pantle, C M Jiang, G Grotzner, M Koch, L I Wagner, I D Sharp, M Stutzmann Control of Band Gap and Band Edge Positions in Gallium-Zinc Oxynitride Grown by Molecular Beam Epitaxy Journal Article Journal of Physical Chemistry C, 124 (14), pp. 7668-7676, 2020, ISSN: 1932-7447. Abstract | Links | Tags: Foundry Inorganic, Solid-Liquid @article{, title = {Control of Band Gap and Band Edge Positions in Gallium-Zinc Oxynitride Grown by Molecular Beam Epitaxy}, author = {M Kraut and E Sirotti and F Pantle and C M Jiang and G Grotzner and M Koch and L I Wagner and I D Sharp and M Stutzmann}, url = {<Go to ISI>://WOS:000526331500009}, doi = {10.1021/acs.jpcc.0c00254}, issn = {1932-7447}, year = {2020}, date = {2020-04-09}, journal = {Journal of Physical Chemistry C}, volume = {124}, number = {14}, pages = {7668-7676}, abstract = {Gallium-zinc oxynitride (GZNO) is a promising material system for solar-driven overall water splitting, as it exhibits a tunable band gap in the visible range, beneficial positions of valence and conduction band edges, and promising long-term stability. Fabrication of GZNO is traditionally accomplished via a solid state reaction pathway. This limits the growth of thin films or large single crystals and the precise control of the composition, which complicates investigations about fundamental properties of the material, including, for example, the influence of the single constituent ratios on the band gap. In this work, we present the growth of GZNO thin films on sapphire by plasma-assisted molecular beam epitaxy (MBE). The thin films exhibit a crystallite size of up to 50 nm and a wurtzite crystal structure with distinct short-range disorder. Variations of Ga/Zn and N/O flux ratios are found to influence the optical absorption edge of the alloy without major impact on the Urbach energy. Controlled change of the composition of the alloy reveals that the band gap reduction is caused by both an increased valence band energy, which is correlated with the N content, and a decrease of the conduction band energy which is induced by increasing Zn content. Based on these findings, GZNO thin films with band gaps of down to 2.0 eV were fabricated and their photoelectrical properties assessed. Using MBE, we overcome compositional restrictions typically associated with stoichiometric GaN:ZnO solid solutions and provide unprecedented access to new compounds within this materials class. In doing so, we elucidate the specific role of individual elements on band edge energetics and demonstrate new routes to band gap engineering for future photocatalytic and photoelectrochemical applications.}, keywords = {Foundry Inorganic, Solid-Liquid}, pubstate = {published}, tppubtype = {article} } Gallium-zinc oxynitride (GZNO) is a promising material system for solar-driven overall water splitting, as it exhibits a tunable band gap in the visible range, beneficial positions of valence and conduction band edges, and promising long-term stability. Fabrication of GZNO is traditionally accomplished via a solid state reaction pathway. This limits the growth of thin films or large single crystals and the precise control of the composition, which complicates investigations about fundamental properties of the material, including, for example, the influence of the single constituent ratios on the band gap. In this work, we present the growth of GZNO thin films on sapphire by plasma-assisted molecular beam epitaxy (MBE). The thin films exhibit a crystallite size of up to 50 nm and a wurtzite crystal structure with distinct short-range disorder. Variations of Ga/Zn and N/O flux ratios are found to influence the optical absorption edge of the alloy without major impact on the Urbach energy. Controlled change of the composition of the alloy reveals that the band gap reduction is caused by both an increased valence band energy, which is correlated with the N content, and a decrease of the conduction band energy which is induced by increasing Zn content. Based on these findings, GZNO thin films with band gaps of down to 2.0 eV were fabricated and their photoelectrical properties assessed. Using MBE, we overcome compositional restrictions typically associated with stoichiometric GaN:ZnO solid solutions and provide unprecedented access to new compounds within this materials class. In doing so, we elucidate the specific role of individual elements on band edge energetics and demonstrate new routes to band gap engineering for future photocatalytic and photoelectrochemical applications. |
| 100. | C A Walenta, C Courtois, S L Kollmannsberger, M Eder, M Tschurl, U Heiz Acs Catalysis, 10 (7), pp. 4080-4091, 2020, ISSN: 2155-5435. Abstract | Links | Tags: Foundry Inorganic, Solid-Liquid @article{, title = {Surface Species in Photocatalytic Methanol Reforming on Pt/TiO2(110): Learning from Surface Science Experiments for Catalytically Relevant Conditions}, author = {C A Walenta and C Courtois and S L Kollmannsberger and M Eder and M Tschurl and U Heiz}, url = {<Go to ISI>://WOS:000526395000011}, doi = {10.1021/acscatal.0c00260}, issn = {2155-5435}, year = {2020}, date = {2020-04-03}, journal = {Acs Catalysis}, volume = {10}, number = {7}, pages = {4080-4091}, abstract = {Photocatalytic hydrogen evolution from methanol is a standard test reaction for photocatalyst materials. Surprisingly, the exact chemical mechanism is still widely discussed in the literature. In order to disentangle photochemical from thermal reaction steps and gain insights on the atomic level, we use a Pt cluster-loaded TiO2(110) photocatalyst in very well-defined environments. Using Auger electron spectroscopy, temperature-programmed desorption/reaction, isotopic labeling, and isothermal photoreactions, it is possible to identify the surface species present on the catalyst under photocatalytic conditions. Furthermore, an initial conditioning of the photocatalyst is observed and attributed to thermal dehydrogenation of methanol to CO species on the cluster. The analysis of the isothermal photoreactions reveals that the photo-oxidation kinetics are not significantly affected by cocatalyst loading. The observed conversion and product distribution of formaldehyde and methyl formate can be rationalized with kinetic parameters gained from the bare TiO2(110) crystal. The work leads to a detailed mechanistic understanding of the surface species and paves the way for an educated microkinetic modeling approach, which may be extended to a variety of noble metal cocatalysts and other TiO2 modifications.}, keywords = {Foundry Inorganic, Solid-Liquid}, pubstate = {published}, tppubtype = {article} } Photocatalytic hydrogen evolution from methanol is a standard test reaction for photocatalyst materials. Surprisingly, the exact chemical mechanism is still widely discussed in the literature. In order to disentangle photochemical from thermal reaction steps and gain insights on the atomic level, we use a Pt cluster-loaded TiO2(110) photocatalyst in very well-defined environments. Using Auger electron spectroscopy, temperature-programmed desorption/reaction, isotopic labeling, and isothermal photoreactions, it is possible to identify the surface species present on the catalyst under photocatalytic conditions. Furthermore, an initial conditioning of the photocatalyst is observed and attributed to thermal dehydrogenation of methanol to CO species on the cluster. The analysis of the isothermal photoreactions reveals that the photo-oxidation kinetics are not significantly affected by cocatalyst loading. The observed conversion and product distribution of formaldehyde and methyl formate can be rationalized with kinetic parameters gained from the bare TiO2(110) crystal. The work leads to a detailed mechanistic understanding of the surface species and paves the way for an educated microkinetic modeling approach, which may be extended to a variety of noble metal cocatalysts and other TiO2 modifications. |
| 99. | J Cao, R J Cogdell, D F Coker, H-G Duan, J Hauer, U Kleinekathöfer, T L C Jansen, T Mančal, R J D Miller, J P Ogilvie, V I Prokhorenko, T Renger, H-S Tan, R Tempelaar, M Thorwart, E Thyrhaug, S Westenhoff, D Zigmantas Quantum biology revisited Journal Article Science Advances, 6 (14), pp. eaaz4888, 2020. Abstract | Links | Tags: Molecularly-Functionalized @article{, title = {Quantum biology revisited}, author = {J Cao and R J Cogdell and D F Coker and H-G Duan and J Hauer and U Kleinekath\"{o}fer and T L C Jansen and T Man\v{c}al and R J D Miller and J P Ogilvie and V I Prokhorenko and T Renger and H-S Tan and R Tempelaar and M Thorwart and E Thyrhaug and S Westenhoff and D Zigmantas}, url = {http://advances.sciencemag.org/content/6/14/eaaz4888.abstract}, doi = {10.1126/sciadv.aaz4888}, year = {2020}, date = {2020-04-01}, journal = {Science Advances}, volume = {6}, number = {14}, pages = {eaaz4888}, abstract = {Photosynthesis is a highly optimized process from which valuable lessons can be learned about the operating principles in nature. Its primary steps involve energy transport operating near theoretical quantum limits in efficiency. Recently, extensive research was motivated by the hypothesis that nature used quantum coherences to direct energy transfer. This body of work, a cornerstone for the field of quantum biology, rests on the interpretation of small-amplitude oscillations in two-dimensional electronic spectra of photosynthetic complexes. This Review discusses recent work reexamining these claims and demonstrates that interexciton coherences are too short lived to have any functional significance in photosynthetic energy transfer. Instead, the observed long-lived coherences originate from impulsively excited vibrations, generally observed in femtosecond spectroscopy. These efforts, collectively, lead to a more detailed understanding of the quantum aspects of dissipation. Nature, rather than trying to avoid dissipation, exploits it via engineering of exciton-bath interaction to create efficient energy flow.}, keywords = {Molecularly-Functionalized}, pubstate = {published}, tppubtype = {article} } Photosynthesis is a highly optimized process from which valuable lessons can be learned about the operating principles in nature. Its primary steps involve energy transport operating near theoretical quantum limits in efficiency. Recently, extensive research was motivated by the hypothesis that nature used quantum coherences to direct energy transfer. This body of work, a cornerstone for the field of quantum biology, rests on the interpretation of small-amplitude oscillations in two-dimensional electronic spectra of photosynthetic complexes. This Review discusses recent work reexamining these claims and demonstrates that interexciton coherences are too short lived to have any functional significance in photosynthetic energy transfer. Instead, the observed long-lived coherences originate from impulsively excited vibrations, generally observed in femtosecond spectroscopy. These efforts, collectively, lead to a more detailed understanding of the quantum aspects of dissipation. Nature, rather than trying to avoid dissipation, exploits it via engineering of exciton-bath interaction to create efficient energy flow. |
| 98. | P T P Ryan, P L Lalaguna, F Haag, M M Braim, P Ding, D J Payne, J V Barth, T L Lee, D P Woodruff, F Allegretti, D A Duncan Validation of the inverted adsorption structure for free-base tetraphenyl porphyrin on Cu(111) Journal Article Chemical Communications, 56 (25), pp. 3681-3684, 2020, ISSN: 1359-7345. Abstract | Links | Tags: Molecularly-Functionalized @article{, title = {Validation of the inverted adsorption structure for free-base tetraphenyl porphyrin on Cu(111)}, author = {P T P Ryan and P L Lalaguna and F Haag and M M Braim and P Ding and D J Payne and J V Barth and T L Lee and D P Woodruff and F Allegretti and D A Duncan}, url = {<Go to ISI>://WOS:000526692700019}, doi = {10.1039/c9cc09638h}, issn = {1359-7345}, year = {2020}, date = {2020-03-28}, journal = {Chemical Communications}, volume = {56}, number = {25}, pages = {3681-3684}, abstract = {Utilising normal incidence X-ray standing waves we rigourously scrutinise the "inverted model" as the adsorption structure of free-base tetraphenyl porphyrin on Cu(111). We demonstrate that the iminic N atoms are anchored at near-bridge adsorption sites on the surface displaced laterally by 1.1 +/- 0.2 angstrom in excellent agreement with previously published calculations.}, keywords = {Molecularly-Functionalized}, pubstate = {published}, tppubtype = {article} } Utilising normal incidence X-ray standing waves we rigourously scrutinise the "inverted model" as the adsorption structure of free-base tetraphenyl porphyrin on Cu(111). We demonstrate that the iminic N atoms are anchored at near-bridge adsorption sites on the surface displaced laterally by 1.1 +/- 0.2 angstrom in excellent agreement with previously published calculations. |
| 97. | B Charles, M T Weller, S Rieger, L E Hatcher, P F Henry, J Feldmann, D Wolverson, C C Wilson Phase Behavior and Substitution Limit of Mixed Cesium-Formamidinium Lead Triiodide Perovskites Journal Article Chemistry of Materials, 32 (6), pp. 2282-2291, 2020, ISSN: 0897-4756. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Phase Behavior and Substitution Limit of Mixed Cesium-Formamidinium Lead Triiodide Perovskites}, author = {B Charles and M T Weller and S Rieger and L E Hatcher and P F Henry and J Feldmann and D Wolverson and C C Wilson}, url = {<Go to ISI>://WOS:000526391300009}, doi = {10.1021/acs.chemmater.9b04032}, issn = {0897-4756}, year = {2020}, date = {2020-03-24}, journal = {Chemistry of Materials}, volume = {32}, number = {6}, pages = {2282-2291}, abstract = {The mixed cation lead iodide perovskite photovoltaics show improved stability following site substitution of cesium ions (Cs+) onto the formamidinium cation sites (FA(+)) of (CH(NH2)(2)PbI3 (FAPbI(3)) and increased resistance to formation of the undesirable.-phase. The structural phase behavior of Cs(0.1)FA(0.9)PbI(3) has been investigated by neutron powder diffraction (NPD), complemented by single crystal and power X-ray diffraction and photoluminescence spectroscopy. The Cs-substitution limit has been determined to be less than 15%, and the cubic alpha-phase, Cs(0.1)FA(0.9)PbI(3), is shown to be synthesizable in bulk and stable at 300 K. On cooling the cubic Cs(0.1)FA(0.9)PbI(3), a slow, second-order cubic to tetragonal transition is observed close to 290 K, with variable temperature NPD indicating the presence of the tetragonal beta-phase, adopting the space group P4/mbm between 290 and 180 K. An orthorhombic phase or twinned tetragonal phase is formed below 180 K, and the temperature for further transition to a disordered state is lowered to 125 K compared to that seen in phase pure alpha-FAPbI(3) (140 K). These results demonstrate the importance of understanding the effect of cation site substitution on structure-property relationships in perovskite materials.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } The mixed cation lead iodide perovskite photovoltaics show improved stability following site substitution of cesium ions (Cs+) onto the formamidinium cation sites (FA(+)) of (CH(NH2)(2)PbI3 (FAPbI(3)) and increased resistance to formation of the undesirable.-phase. The structural phase behavior of Cs(0.1)FA(0.9)PbI(3) has been investigated by neutron powder diffraction (NPD), complemented by single crystal and power X-ray diffraction and photoluminescence spectroscopy. The Cs-substitution limit has been determined to be less than 15%, and the cubic alpha-phase, Cs(0.1)FA(0.9)PbI(3), is shown to be synthesizable in bulk and stable at 300 K. On cooling the cubic Cs(0.1)FA(0.9)PbI(3), a slow, second-order cubic to tetragonal transition is observed close to 290 K, with variable temperature NPD indicating the presence of the tetragonal beta-phase, adopting the space group P4/mbm between 290 and 180 K. An orthorhombic phase or twinned tetragonal phase is formed below 180 K, and the temperature for further transition to a disordered state is lowered to 125 K compared to that seen in phase pure alpha-FAPbI(3) (140 K). These results demonstrate the importance of understanding the effect of cation site substitution on structure-property relationships in perovskite materials. |
| 96. | P Mao, C Liu, F Song, M Han, S A Maier, S Zhang Manipulating disordered plasmonic systems by external cavity with transition from broadband absorption to reconfigurable reflection Journal Article Nature Communications, 11 (1), pp. 1538, 2020, ISSN: 2041-1723. Abstract | Links | Tags: Foundry Organic @article{, title = {Manipulating disordered plasmonic systems by external cavity with transition from broadband absorption to reconfigurable reflection}, author = {P Mao and C Liu and F Song and M Han and S A Maier and S Zhang}, url = {https://doi.org/10.1038/s41467-020-15349-y}, doi = {10.1038/s41467-020-15349-y}, issn = {2041-1723}, year = {2020}, date = {2020-03-24}, journal = {Nature Communications}, volume = {11}, number = {1}, pages = {1538}, abstract = {Disordered biostructures are ubiquitous in nature, usually generating white or black colours due to their broadband optical response and robustness to perturbations. Through judicious design, disordered nanostructures have been realised in artificial systems, with unique properties for light localisation, photon transportation and energy harvesting. On the other hand, the tunability of disordered systems with a broadband response has been scarcely explored. Here, we achieve the controlled manipulation of disordered plasmonic systems, realising the transition from broadband absorption to tunable reflection through deterministic control of the coupling to an external cavity. Starting from a generalised model, we realise disordered systems composed of plasmonic nanoclusters that either operate as a broadband absorber or with a reconfigurable reflection band throughout the visible. Not limited to its significance for the further understanding of the physics of disorder, our disordered plasmonic system provides a novel platform for various practical application such as structural colour patterning.}, keywords = {Foundry Organic}, pubstate = {published}, tppubtype = {article} } Disordered biostructures are ubiquitous in nature, usually generating white or black colours due to their broadband optical response and robustness to perturbations. Through judicious design, disordered nanostructures have been realised in artificial systems, with unique properties for light localisation, photon transportation and energy harvesting. On the other hand, the tunability of disordered systems with a broadband response has been scarcely explored. Here, we achieve the controlled manipulation of disordered plasmonic systems, realising the transition from broadband absorption to tunable reflection through deterministic control of the coupling to an external cavity. Starting from a generalised model, we realise disordered systems composed of plasmonic nanoclusters that either operate as a broadband absorber or with a reconfigurable reflection band throughout the visible. Not limited to its significance for the further understanding of the physics of disorder, our disordered plasmonic system provides a novel platform for various practical application such as structural colour patterning. |
| 95. | K S Wienhold, X Y Jiang, P Muller-Buschbaum Organic solar cells probed with advanced neutron scattering techniques Journal Article Applied Physics Letters, 116 (12), 2020, ISSN: 0003-6951. Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized @article{, title = {Organic solar cells probed with advanced neutron scattering techniques}, author = {K S Wienhold and X Y Jiang and P Muller-Buschbaum}, url = {<Go to ISI>://WOS:000522430600001}, doi = {10.1063/5.0003997}, issn = {0003-6951}, year = {2020}, date = {2020-03-23}, journal = {Applied Physics Letters}, volume = {116}, number = {12}, abstract = {Neutron scattering techniques provide unique insights into the active layer morphology of organic solar cells. The nanoscale morphology, the thin film vertical composition, and the intermixing on a molecular level, which all strongly have an impact on the performance of organic solar cells, can be probed with neutrons. In addition to the static structure, also fast dynamics occurring in the active material is accessible with neutrons. This perspective letter highlights the power of grazing incidence small angle neutron scattering and quasi-elastic neutron scattering experiments after shortly introducing into the working principle of organic solar cells.}, keywords = {Foundry Organic, Molecularly-Functionalized}, pubstate = {published}, tppubtype = {article} } Neutron scattering techniques provide unique insights into the active layer morphology of organic solar cells. The nanoscale morphology, the thin film vertical composition, and the intermixing on a molecular level, which all strongly have an impact on the performance of organic solar cells, can be probed with neutrons. In addition to the static structure, also fast dynamics occurring in the active material is accessible with neutrons. This perspective letter highlights the power of grazing incidence small angle neutron scattering and quasi-elastic neutron scattering experiments after shortly introducing into the working principle of organic solar cells. |
| 94. | D Yang, B Cao, V Korstgens, N Saxena, N Li, C Bilko, S Grott, W Chen, X Y Jiang, J E Heger, S Bernstorff, P Muller-Buschbaum Tailoring Morphology Compatibility and Device Stability by Adding PBDTTPD-COOH as Third Component to Fullerene-Based Polymer Solar Cells Journal Article Acs Applied Energy Materials, 3 (3), pp. 2604-2613, 2020, ISSN: 2574-0962. Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized @article{, title = {Tailoring Morphology Compatibility and Device Stability by Adding PBDTTPD-COOH as Third Component to Fullerene-Based Polymer Solar Cells}, author = {D Yang and B Cao and V Korstgens and N Saxena and N Li and C Bilko and S Grott and W Chen and X Y Jiang and J E Heger and S Bernstorff and P Muller-Buschbaum}, url = {<Go to ISI>://WOS:000526598300061}, doi = {10.1021/acsaem.9b02290}, issn = {2574-0962}, year = {2020}, date = {2020-03-23}, journal = {Acs Applied Energy Materials}, volume = {3}, number = {3}, pages = {2604-2613}, abstract = {The crystallinity and morphology of polymer and fullerene have a profound influence on the performance of bulk heterojunction (BHJ) organic photovoltaic devices. The poor compatibility of donor and acceptor molecules in the BHJs hinders the further improvement of the device performance and stability in organic solar cells. In this work, the conjugated polymer PBDTTPD-COOH is introduced as a third component into BHJ films of PTB7-Th:PC71BM and PffBT4T-2OD:PC71BM to improve the crystallinity and morphology. The crystallinity of both donor polymers is enhanced and more face-on orientated crystals are observed in the corresponding films, which is correlated with the improvement of the current density of the related solar cells. Also, the improved BHJ morphology leads to an increased fill factor. Furthermore, the device stability significantly increases by the addition of the third component PBDTTPD-COOH. The T80 lifetime value is enhanced 10 times in the doped devices as compared with the binary solar cells in the case of the PTB7-Th:PC71BM series.}, keywords = {Foundry Organic, Molecularly-Functionalized}, pubstate = {published}, tppubtype = {article} } The crystallinity and morphology of polymer and fullerene have a profound influence on the performance of bulk heterojunction (BHJ) organic photovoltaic devices. The poor compatibility of donor and acceptor molecules in the BHJs hinders the further improvement of the device performance and stability in organic solar cells. In this work, the conjugated polymer PBDTTPD-COOH is introduced as a third component into BHJ films of PTB7-Th:PC71BM and PffBT4T-2OD:PC71BM to improve the crystallinity and morphology. The crystallinity of both donor polymers is enhanced and more face-on orientated crystals are observed in the corresponding films, which is correlated with the improvement of the current density of the related solar cells. Also, the improved BHJ morphology leads to an increased fill factor. Furthermore, the device stability significantly increases by the addition of the third component PBDTTPD-COOH. The T80 lifetime value is enhanced 10 times in the doped devices as compared with the binary solar cells in the case of the PTB7-Th:PC71BM series. |
| 93. | J Kiemle, F Sigger, M Lorke, B Miller, K Watanabe, T Taniguchi, A W Holleitner, U Wurstbauer Control of the orbital character of indirect excitons in MoS2/WS2 heterobilayers Journal Article Physical Review B, 101 (12), pp. 121404, 2020. Links | Tags: Solid-Solid @article{, title = {Control of the orbital character of indirect excitons in MoS2/WS2 heterobilayers}, author = {J Kiemle and F Sigger and M Lorke and B Miller and K Watanabe and T Taniguchi and A W Holleitner and U Wurstbauer}, url = {https://link.aps.org/doi/10.1103/PhysRevB.101.121404}, doi = {10.1103/PhysRevB.101.121404}, year = {2020}, date = {2020-03-18}, journal = {Physical Review B}, volume = {101}, number = {12}, pages = {121404}, keywords = {Solid-Solid}, pubstate = {published}, tppubtype = {article} } |
| 92. | J Skotnitzki, A Kremsmair, B Kicin, R Saeb, V Ruf, P Knochel Synthesis-Stuttgart, 52 (6), pp. 873-881, 2020, ISSN: 0039-7881. Abstract | Links | Tags: Foundry Organic @article{, title = {Stereoselective anti-S(N)2 '-Substitutions of Secondary Alkylcopper-Zinc Reagents with Allylic Epoxides: Total Synthesis of (3S,6R,7S)-Zingiberenol}, author = {J Skotnitzki and A Kremsmair and B Kicin and R Saeb and V Ruf and P Knochel}, url = {<Go to ISI>://WOS:000519236300009}, doi = {10.1055/s-0039-1690766}, issn = {0039-7881}, year = {2020}, date = {2020-03-17}, journal = {Synthesis-Stuttgart}, volume = {52}, number = {6}, pages = {873-881}, abstract = {Chiral secondary mixed alkylcopper-zinc reagents were prepared from the corresponding alkyl iodides and reacted with allylic epoxides via an anti -S (N) 2 '-substitution and retention of configuration of the chiral alkylorganometallic, leading to chiral allylic alcohols. This method was used in a total synthesis of the natural product (3 S ,6 R ,7 S )-zingiberenol in 8 steps and 9.7% overall yield [dr (3 S ,6 R ) = 99:1; dr (6 R ,7 S ) = 81:19] starting from commercially available 3-methyl-2-cyclohexenone.}, keywords = {Foundry Organic}, pubstate = {published}, tppubtype = {article} } Chiral secondary mixed alkylcopper-zinc reagents were prepared from the corresponding alkyl iodides and reacted with allylic epoxides via an anti -S (N) 2 '-substitution and retention of configuration of the chiral alkylorganometallic, leading to chiral allylic alcohols. This method was used in a total synthesis of the natural product (3 S ,6 R ,7 S )-zingiberenol in 8 steps and 9.7% overall yield [dr (3 S ,6 R ) = 99:1; dr (6 R ,7 S ) = 81:19] starting from commercially available 3-methyl-2-cyclohexenone. |
| 91. | S Ohno, T Bernges, J Buchheim, M Duchardt, A-K Hatz, M A Kraft, H Kwak, A L Santhosha, Z Liu, N Minafra, F Tsuji, A Sakuda, R Schlem, S Xiong, Z Zhang, P Adelhelm, H Chen, A Hayashi, Y S Jung, B V Lotsch, B Roling, N M Vargas-Barbosa, W G Zeier How Certain Are the Reported Ionic Conductivities of Thiophosphate-Based Solid Electrolytes? An Interlaboratory Study Journal Article ACS Energy Letters, 5 (3), pp. 910-915, 2020. Links | Tags: Solid-Solid @article{, title = {How Certain Are the Reported Ionic Conductivities of Thiophosphate-Based Solid Electrolytes? An Interlaboratory Study}, author = {S Ohno and T Bernges and J Buchheim and M Duchardt and A-K Hatz and M A Kraft and H Kwak and A L Santhosha and Z Liu and N Minafra and F Tsuji and A Sakuda and R Schlem and S Xiong and Z Zhang and P Adelhelm and H Chen and A Hayashi and Y S Jung and B V Lotsch and B Roling and N M Vargas-Barbosa and W G Zeier}, url = {https://doi.org/10.1021/acsenergylett.9b02764}, doi = {10.1021/acsenergylett.9b02764}, year = {2020}, date = {2020-03-13}, journal = {ACS Energy Letters}, volume = {5}, number = {3}, pages = {910-915}, keywords = {Solid-Solid}, pubstate = {published}, tppubtype = {article} } |
| 90. | M Kick, C Grosu, M Schuderer, C Scheurer, H Oberhofer Mobile Small Polarons Qualitatively Explain Conductivity in Lithium Titanium Oxide Battery Electrodes Journal Article Journal of Physical Chemistry Letters, 11 (7), pp. 2535-2540, 2020, ISSN: 1948-7185. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Mobile Small Polarons Qualitatively Explain Conductivity in Lithium Titanium Oxide Battery Electrodes}, author = {M Kick and C Grosu and M Schuderer and C Scheurer and H Oberhofer}, url = {<Go to ISI>://WOS:000526348400022}, doi = {10.1021/acs.jpclett.0c00568}, issn = {1948-7185}, year = {2020}, date = {2020-03-12}, journal = {Journal of Physical Chemistry Letters}, volume = {11}, number = {7}, pages = {2535-2540}, abstract = {Lithium titanium oxide Li4Ti5O12 is an intriguing anode material promising particularly long-life batteries, due to its remarkable phase stability during (dis)charging of the cell. However, its usage is limited by its low intrinsic electronic conductivity. Introducing oxygen vacancies can be one method for overcoming this drawback, possibly by altering the charge carrier transport mechanism. We use Hubbard corrected density functional theory to show that polaronic states in combination with a possible hopping mechanism can play a crucial role in the experimentally observed increase in electronic conductivity. To gauge polaronic charge mobility, we compute the relative stabilities of different localization patterns and estimate polaron hopping barrier heights.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Lithium titanium oxide Li4Ti5O12 is an intriguing anode material promising particularly long-life batteries, due to its remarkable phase stability during (dis)charging of the cell. However, its usage is limited by its low intrinsic electronic conductivity. Introducing oxygen vacancies can be one method for overcoming this drawback, possibly by altering the charge carrier transport mechanism. We use Hubbard corrected density functional theory to show that polaronic states in combination with a possible hopping mechanism can play a crucial role in the experimentally observed increase in electronic conductivity. To gauge polaronic charge mobility, we compute the relative stabilities of different localization patterns and estimate polaron hopping barrier heights. |
| 89. | J Fichtner, S Watzele, B Garlyyev, R M Kluge, F Haimerl, H A El-Sayed, W J Li, F M Maillard, L Dubau, R Chattot, J Michalicka, J M Macak, W Wang, D Wang, T Gigl, C Hugenschmidt, A S Bandarenka Tailoring the Oxygen Reduction Activity of Pt Nanoparticles through Surface Defects: A Simple Top-Down Approach Journal Article Acs Catalysis, 10 (5), pp. 3131-3142, 2020, ISSN: 2155-5435. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Tailoring the Oxygen Reduction Activity of Pt Nanoparticles through Surface Defects: A Simple Top-Down Approach}, author = {J Fichtner and S Watzele and B Garlyyev and R M Kluge and F Haimerl and H A El-Sayed and W J Li and F M Maillard and L Dubau and R Chattot and J Michalicka and J M Macak and W Wang and D Wang and T Gigl and C Hugenschmidt and A S Bandarenka}, url = {<Go to ISI>://WOS:000518876300024}, doi = {10.1021/acscatal.9b04974}, issn = {2155-5435}, year = {2020}, date = {2020-03-06}, journal = {Acs Catalysis}, volume = {10}, number = {5}, pages = {3131-3142}, abstract = {Results from Pt model catalyst surfaces have demonstrated that surface defects, in particular surface concavities, can improve the oxygen reduction reaction (ORR) kinetics. It is, however, a challenging task to synthesize nanostructured catalysts with such defective surfaces. Hence, we present a one-step and upscalable top-down approach to produce a Pt/C catalyst (with similar to 3 nm Pt nanoparticle diameter). Using high-resolution transmission electron microscopy and tomography, electrochemical techniques, high-energy X-ray measurements, and positron annihilation spectroscopy, we provide evidence of a high density of surface defects (including surface concavities). The ORR activity of the developed catalyst exceeds that of a commercial Pt/C catalyst, at least 2.7 times in terms of specific activity (similar to 1.62 mA/cm(Pt)(2), at 0.9 V vs the reversible hydrogen electrode) and at least 1.7 times in terms of mass activity (similar to 712 mA/mg(Pt)), which can be correlated to the enhanced amount of surface defects. In addition, the technique used here reduces the complexity of the synthesis (and therefore production costs) in comparison to state of the art bottom-up techniques.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Results from Pt model catalyst surfaces have demonstrated that surface defects, in particular surface concavities, can improve the oxygen reduction reaction (ORR) kinetics. It is, however, a challenging task to synthesize nanostructured catalysts with such defective surfaces. Hence, we present a one-step and upscalable top-down approach to produce a Pt/C catalyst (with similar to 3 nm Pt nanoparticle diameter). Using high-resolution transmission electron microscopy and tomography, electrochemical techniques, high-energy X-ray measurements, and positron annihilation spectroscopy, we provide evidence of a high density of surface defects (including surface concavities). The ORR activity of the developed catalyst exceeds that of a commercial Pt/C catalyst, at least 2.7 times in terms of specific activity (similar to 1.62 mA/cm(Pt)(2), at 0.9 V vs the reversible hydrogen electrode) and at least 1.7 times in terms of mass activity (similar to 712 mA/mg(Pt)), which can be correlated to the enhanced amount of surface defects. In addition, the technique used here reduces the complexity of the synthesis (and therefore production costs) in comparison to state of the art bottom-up techniques. |
| 88. | S J Hao, M Hetzl, V F Kunzelmann, S Matich, Q L Sai, C T Xia, I D Sharp, M Stutzmann Sub-bandgap optical spectroscopy of epitaxial beta-Ga2O3 thin films Journal Article Applied Physics Letters, 116 (9), 2020, ISSN: 0003-6951. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Sub-bandgap optical spectroscopy of epitaxial beta-Ga2O3 thin films}, author = {S J Hao and M Hetzl and V F Kunzelmann and S Matich and Q L Sai and C T Xia and I D Sharp and M Stutzmann}, url = {<Go to ISI>://WOS:000519225900001}, doi = {10.1063/1.5143393}, issn = {0003-6951}, year = {2020}, date = {2020-03-02}, journal = {Applied Physics Letters}, volume = {116}, number = {9}, abstract = {Room temperature sub-gap optical absorption spectra measured by photothermal deflection spectroscopy were investigated for hetero- and homo-epitaxial beta-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy as well as for a bulk crystal. The absorption spectra show a pronounced exponential Urbach tail with slope parameters of 120-150 meV in the spectral region between 4.5 and 5 eV, indicating an unusually large self-trapping energy of excitons. In addition, an absorption band related to deep defects is observed in the spectral region from 2.5 to 4.5 eV. The steepness of the Urbach tail as well as the strength of the defect-related absorption can be influenced and optimized by annealing at 900-1000 degrees C in an oxygen atmosphere. Similar features were also observed for bulk beta-Ga2O3 crystals and for homoepitaxial beta-Ga2O3 layers. The present results for beta-Ga2O3 are compared and discussed in the context of similar measurements for other wide-bandgap semiconductors of current interest in electronics and photocatalysis: GaN, ZnO, TiO2, and BiVO4.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Room temperature sub-gap optical absorption spectra measured by photothermal deflection spectroscopy were investigated for hetero- and homo-epitaxial beta-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy as well as for a bulk crystal. The absorption spectra show a pronounced exponential Urbach tail with slope parameters of 120-150 meV in the spectral region between 4.5 and 5 eV, indicating an unusually large self-trapping energy of excitons. In addition, an absorption band related to deep defects is observed in the spectral region from 2.5 to 4.5 eV. The steepness of the Urbach tail as well as the strength of the defect-related absorption can be influenced and optimized by annealing at 900-1000 degrees C in an oxygen atmosphere. Similar features were also observed for bulk beta-Ga2O3 crystals and for homoepitaxial beta-Ga2O3 layers. The present results for beta-Ga2O3 are compared and discussed in the context of similar measurements for other wide-bandgap semiconductors of current interest in electronics and photocatalysis: GaN, ZnO, TiO2, and BiVO4. |
| 87. | R S Markl, N Hohn, E Hupf, L Biessmann, V Korstgens, L P Kreuzer, G Mangiapia, M Pomm, A Kriele, E Rivard, P Muller-Buschbaum Comparing the backfilling of mesoporous titania thin films with hole conductors of different sizes sharing the same mass density Journal Article Iucrj, 7 , pp. 268-275, 2020, ISSN: 2052-2525. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Comparing the backfilling of mesoporous titania thin films with hole conductors of different sizes sharing the same mass density}, author = {R S Markl and N Hohn and E Hupf and L Biessmann and V Korstgens and L P Kreuzer and G Mangiapia and M Pomm and A Kriele and E Rivard and P Muller-Buschbaum}, url = {<Go to ISI>://WOS:000518799300015}, doi = {10.1107/s2052252520000913}, issn = {2052-2525}, year = {2020}, date = {2020-03-01}, journal = {Iucrj}, volume = {7}, pages = {268-275}, abstract = {Efficient infiltration of a mesoporous titania matrix with conducting organic polymers or small molecules is one key challenge to overcome for hybrid photovoltaic devices. A quantitative analysis of the backfilling efficiency with time-of-flight grazing incidence small-angle neutron scattering (ToF-GISANS) and scanning electron microscopy (SEM) measurements is presented. Differences in the morphology due to the backfilling of mesoporous titania thin films are compared for the macromolecule poly[4,8-bis(5-(2-ethylhexyl)-thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] (PTB7-Th) and the heavy-element containing small molecule 2-pinacolboronate-3-phenylphenanthro[9,10-b]tellurophene(PhenTe-BPinPh). Hence, a 1.7 times higher backfilling efficiency of almost 70% is achieved for the small molecule PhenTe-BPinPh compared with the polymer PTB7-Th despite sharing the same volumetric mass density. The precise characterization of structural changes due to backfilling reveals that the volumetric density of backfilled materials plays a minor role in obtaining good backfilling efficiencies and interfaces with large surface contact.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Efficient infiltration of a mesoporous titania matrix with conducting organic polymers or small molecules is one key challenge to overcome for hybrid photovoltaic devices. A quantitative analysis of the backfilling efficiency with time-of-flight grazing incidence small-angle neutron scattering (ToF-GISANS) and scanning electron microscopy (SEM) measurements is presented. Differences in the morphology due to the backfilling of mesoporous titania thin films are compared for the macromolecule poly[4,8-bis(5-(2-ethylhexyl)-thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] (PTB7-Th) and the heavy-element containing small molecule 2-pinacolboronate-3-phenylphenanthro[9,10-b]tellurophene(PhenTe-BPinPh). Hence, a 1.7 times higher backfilling efficiency of almost 70% is achieved for the small molecule PhenTe-BPinPh compared with the polymer PTB7-Th despite sharing the same volumetric mass density. The precise characterization of structural changes due to backfilling reveals that the volumetric density of backfilled materials plays a minor role in obtaining good backfilling efficiencies and interfaces with large surface contact. |
| 86. | S Oviedo-Casado, F Šanda, J Hauer, J Prior Magnetic pulses enable multidimensional optical spectroscopy of dark states Journal Article The Journal of Chemical Physics, 152 (8), pp. 084201, 2020, ISSN: 0021-9606. Links | Tags: Solid-Liquid @article{, title = {Magnetic pulses enable multidimensional optical spectroscopy of dark states}, author = {S Oviedo-Casado and F \v{S}anda and J Hauer and J Prior}, url = {https://doi.org/10.1063/1.5139409}, doi = {10.1063/1.5139409}, issn = {0021-9606}, year = {2020}, date = {2020-02-28}, journal = {The Journal of Chemical Physics}, volume = {152}, number = {8}, pages = {084201}, keywords = {Solid-Liquid}, pubstate = {published}, tppubtype = {article} } |
| 85. | L Hüttenhofer, F Eckmann, A Lauri, J Cambiasso, E Pensa, Y Li, E Cortés, I D Sharp, S A Maier Anapole Excitations in Oxygen-Vacancy-Rich TiO2–x Nanoresonators: Tuning the Absorption for Photocatalysis in the Visible Spectrum Journal Article ACS Nano, 14 (2), pp. 2456-2464, 2020, ISSN: 1936-0851. Links | Tags: Foundry Inorganic @article{, title = {Anapole Excitations in Oxygen-Vacancy-Rich TiO2\textendashx Nanoresonators: Tuning the Absorption for Photocatalysis in the Visible Spectrum}, author = {L H\"{u}ttenhofer and F Eckmann and A Lauri and J Cambiasso and E Pensa and Y Li and E Cort\'{e}s and I D Sharp and S A Maier}, url = {https://doi.org/10.1021/acsnano.9b09987}, doi = {10.1021/acsnano.9b09987}, issn = {1936-0851}, year = {2020}, date = {2020-02-25}, journal = {ACS Nano}, volume = {14}, number = {2}, pages = {2456-2464}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } |
| 84. | H Bi, C A Palma, Y X Gong, K Stallhofer, M Nuber, C Jing, F Meggendorfer, S Z Wen, C Y Yam, R Kienberger, M Elbing, M Mayor, H Iglev, J V Barth, J Reichert Electron-Phonon Coupling in Current-Driven Single-Molecule Junctions Journal Article Journal of the American Chemical Society, 142 (7), pp. 3384-3391, 2020, ISSN: 0002-7863. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Electron-Phonon Coupling in Current-Driven Single-Molecule Junctions}, author = {H Bi and C A Palma and Y X Gong and K Stallhofer and M Nuber and C Jing and F Meggendorfer and S Z Wen and C Y Yam and R Kienberger and M Elbing and M Mayor and H Iglev and J V Barth and J Reichert}, url = {<Go to ISI>://WOS:000515214000020}, doi = {10.1021/jacs.9b07757}, issn = {0002-7863}, year = {2020}, date = {2020-02-19}, journal = {Journal of the American Chemical Society}, volume = {142}, number = {7}, pages = {3384-3391}, abstract = {Vibrational excitations provoked by coupling effects during charge transport through single molecules are intrinsic energy dissipation phenomena, in close analogy to electron-phonon coupling in solids. One fundamental challenge in molecular electronics is the quantitative determination of charge-vibrational (electron-phonon) coupling for single-molecule junctions. The ability to record electron-phonon coupling phenomena at the single-molecule level is a key prerequisite to fully rationalize and optimize charge-transport efficiencies for specific molecular configurations and currents. Here we exemplarily determine the pertaining coupling characteristics for a current-carrying chemically well-defined molecule by synchronous vibrational and current- voltage spectroscopy. These metal-molecule-metal junction insights are complemented by time-resolved infrared spectroscopy to assess the intramolecular vibrational relaxation dynamics. By measuring and analyzing the steady-state vibrational distribution during transient charge transport in a bis-phenylethynyl-anthracene derivative using anti-Stokes Raman scattering, we find similar to 0.5 vibrational excitations per elementary charge passing through the metal-moleculemetal junction, by means of a rate model ansatz and quantum-chemical calculations.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } Vibrational excitations provoked by coupling effects during charge transport through single molecules are intrinsic energy dissipation phenomena, in close analogy to electron-phonon coupling in solids. One fundamental challenge in molecular electronics is the quantitative determination of charge-vibrational (electron-phonon) coupling for single-molecule junctions. The ability to record electron-phonon coupling phenomena at the single-molecule level is a key prerequisite to fully rationalize and optimize charge-transport efficiencies for specific molecular configurations and currents. Here we exemplarily determine the pertaining coupling characteristics for a current-carrying chemically well-defined molecule by synchronous vibrational and current- voltage spectroscopy. These metal-molecule-metal junction insights are complemented by time-resolved infrared spectroscopy to assess the intramolecular vibrational relaxation dynamics. By measuring and analyzing the steady-state vibrational distribution during transient charge transport in a bis-phenylethynyl-anthracene derivative using anti-Stokes Raman scattering, we find similar to 0.5 vibrational excitations per elementary charge passing through the metal-moleculemetal junction, by means of a rate model ansatz and quantum-chemical calculations. |
| 83. | P Zimmermann, A W Holleitner On-site tuning of the carrier lifetime in silicon for on-chip THz circuits using a focused beam of helium ions Journal Article Applied Physics Letters, 116 (7), pp. 073501, 2020, ISSN: 0003-6951. Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {On-site tuning of the carrier lifetime in silicon for on-chip THz circuits using a focused beam of helium ions}, author = {P Zimmermann and A W Holleitner}, url = {https://doi.org/10.1063/1.5143421}, doi = {10.1063/1.5143421}, issn = {0003-6951}, year = {2020}, date = {2020-02-18}, journal = {Applied Physics Letters}, volume = {116}, number = {7}, pages = {073501}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } |
| 82. | S Harm, A-K Hatz, C Schneider, C Hoefer, C Hoch, B V Lotsch Finding the Right Blend: Interplay Between Structure and Sodium Ion Conductivity in the System Na5AlS4–Na4SiS4 Journal Article Frontiers in Chemistry, 8 , pp. 90, 2020, ISSN: 2296-2646. Abstract | Links | Tags: Solid-Solid @article{, title = {Finding the Right Blend: Interplay Between Structure and Sodium Ion Conductivity in the System Na5AlS4\textendashNa4SiS4}, author = {S Harm and A-K Hatz and C Schneider and C Hoefer and C Hoch and B V Lotsch}, url = {https://www.frontiersin.org/article/10.3389/fchem.2020.00090}, doi = {10.3389/fchem.2020.00090}, issn = {2296-2646}, year = {2020}, date = {2020-02-18}, journal = {Frontiers in Chemistry}, volume = {8}, pages = {90}, abstract = {The rational design of high performance sodium solid electrolytes is one of the key challenges in modern battery research. In this work, we identify new sodium ion conductors in the substitution series Na_{5-x}Al_{1-x}Si_{x}S4 (0 ≤ x ≤ 1), which are entirely based on earth-abundant elements. These compounds exhibit conductivities ranging from 1.64 · 10^{−7} for Na_{4}SiS_{4} to 2.04 · 10^{−5} for Na_{8.5}(AlS_{4})_{0.5}(SiS_{4})_{1.5} (x = 0.75). We determined the crystal structures of the Na^{+}-ion conductors Na_{4}SiS_{4} as well as hitherto unknown Na_{5}AlS_{4} and Na_{9}(AlS_{4})(SiS_{4}). Na^{+}-ion conduction pathways were calculated by bond valence energy landscape (BVEL) calculations for all new structures highlighting the influence of the local coordination symmetry of sodium ions on the energy landscape within this family. Our findings show that the interplay of charge carrier concentration and low site symmetry of sodium ions can enhance the conductivity by several orders of magnitude.}, keywords = {Solid-Solid}, pubstate = {published}, tppubtype = {article} } The rational design of high performance sodium solid electrolytes is one of the key challenges in modern battery research. In this work, we identify new sodium ion conductors in the substitution series Na5-xAl1-xSixS4 (0 ≤ x ≤ 1), which are entirely based on earth-abundant elements. These compounds exhibit conductivities ranging from 1.64 · 10−7 for Na4SiS4 to 2.04 · 10−5 for Na8.5(AlS4)0.5(SiS4)1.5 (x = 0.75). We determined the crystal structures of the Na+-ion conductors Na4SiS4 as well as hitherto unknown Na5AlS4 and Na9(AlS4)(SiS4). Na+-ion conduction pathways were calculated by bond valence energy landscape (BVEL) calculations for all new structures highlighting the influence of the local coordination symmetry of sodium ions on the energy landscape within this family. Our findings show that the interplay of charge carrier concentration and low site symmetry of sodium ions can enhance the conductivity by several orders of magnitude. |
| 81. | V Giegold, L Lange, R Ciesielski, A Hartschuh Non-linear Raman scattering intensities in graphene Journal Article Nanoscale, 2020, ISSN: 2040-3364. Abstract | Links | Tags: Foundry Inorganic @article{, title = {Non-linear Raman scattering intensities in graphene}, author = {V Giegold and L Lange and R Ciesielski and A Hartschuh}, url = {http://dx.doi.org/10.1039/C9NR10654E}, doi = {10.1039/C9NR10654E}, issn = {2040-3364}, year = {2020}, date = {2020-02-18}, journal = {Nanoscale}, abstract = {We show that the Raman scattering signals of the two dominant Raman bands G and 2D of graphene sensitively depend on the laser intensity in opposite ways. High electronic temperatures reached for pulsed laser excitation lead to an asymmetric Fermi\textendashDirac distribution at the different optically resonant states contributing to Raman scattering. This results in a partial Pauli blocking of destructively interfering quantum pathways for G band scattering, which is observed as a super-linear increase of the G band intensity with laser power. The 2D band, on the other hand, exhibits sub-linear intensity scaling due to the blocking of constructively interfering contributions. The opposite intensity dependencies of the two bands are found to reduce the observed 2D/G ratio, a key quantity used for characterizing graphene samples, by more than factor two for electronic temperatures around 3000 K.}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } We show that the Raman scattering signals of the two dominant Raman bands G and 2D of graphene sensitively depend on the laser intensity in opposite ways. High electronic temperatures reached for pulsed laser excitation lead to an asymmetric Fermi–Dirac distribution at the different optically resonant states contributing to Raman scattering. This results in a partial Pauli blocking of destructively interfering quantum pathways for G band scattering, which is observed as a super-linear increase of the G band intensity with laser power. The 2D band, on the other hand, exhibits sub-linear intensity scaling due to the blocking of constructively interfering contributions. The opposite intensity dependencies of the two bands are found to reduce the observed 2D/G ratio, a key quantity used for characterizing graphene samples, by more than factor two for electronic temperatures around 3000 K. |
| 80. | N Li, L Song, N Hohn, S Saxena, W Cao, X Y Jiang, P Muller-Buschbaum Nanoscale crystallization of a low band gap polymer in printed titania mesopores Journal Article Nanoscale, 12 (6), pp. 4085-4093, 2020, ISSN: 2040-3364. Abstract | Links | Tags: Foundry Inorganic, Solid-Solid @article{, title = {Nanoscale crystallization of a low band gap polymer in printed titania mesopores}, author = {N Li and L Song and N Hohn and S Saxena and W Cao and X Y Jiang and P Muller-Buschbaum}, url = {<Go to ISI>://WOS:000515391000053}, doi = {10.1039/c9nr08055d}, issn = {2040-3364}, year = {2020}, date = {2020-02-14}, journal = {Nanoscale}, volume = {12}, number = {6}, pages = {4085-4093}, abstract = {The crystallization behavior of the low band gap polymer poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3 '''-di(2-octyldodecyl)2,2 ';5 ',2 '';5 '',2 '''-quaterthiophen-5,5 '''-diyl)] (PffBT4T-2OD) induced in printed mesoporous titania films with different pore sizes is studied to optimize the crystal orientation for an application in hybrid solar cells. The correlation between the crystal structure of PffBT4T-2OD and the titania pore size is investigated with a combination of grazing incidence wide-angle X-ray scattering (GIWAXS) and grazing incidence small-angle X-ray scattering (GISAXS). For comparison, poly(3-hexylthiophene) (P3HT) is also backfilled into the same four types of printed titania mesoporous scaffolds. Both, lattice constants and crystal sizes of edge-on oriented P3HT crystals decrease with increasing the titania pore size. Similarly and irrespective of the crystal orientation, a denser stacking of PffBT4T-2OD chains is found for larger pore sizes of the titania matrix. For an edge-on orientation, also bigger PffBT4T-2OD crystals are favorably formed in smaller pores, whereas for a face-on orientation, PffBT4T-2OD crystals increase with increasing size of the titania pores. Thus, the best ratio of face-on to edge-on crystals for PffBT4T-2OD is obtained through infiltration into large titania pores.}, keywords = {Foundry Inorganic, Solid-Solid}, pubstate = {published}, tppubtype = {article} } The crystallization behavior of the low band gap polymer poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3 '''-di(2-octyldodecyl)2,2 ';5 ',2 '';5 '',2 '''-quaterthiophen-5,5 '''-diyl)] (PffBT4T-2OD) induced in printed mesoporous titania films with different pore sizes is studied to optimize the crystal orientation for an application in hybrid solar cells. The correlation between the crystal structure of PffBT4T-2OD and the titania pore size is investigated with a combination of grazing incidence wide-angle X-ray scattering (GIWAXS) and grazing incidence small-angle X-ray scattering (GISAXS). For comparison, poly(3-hexylthiophene) (P3HT) is also backfilled into the same four types of printed titania mesoporous scaffolds. Both, lattice constants and crystal sizes of edge-on oriented P3HT crystals decrease with increasing the titania pore size. Similarly and irrespective of the crystal orientation, a denser stacking of PffBT4T-2OD chains is found for larger pore sizes of the titania matrix. For an edge-on orientation, also bigger PffBT4T-2OD crystals are favorably formed in smaller pores, whereas for a face-on orientation, PffBT4T-2OD crystals increase with increasing size of the titania pores. Thus, the best ratio of face-on to edge-on crystals for PffBT4T-2OD is obtained through infiltration into large titania pores. |
| 79. | M Rück, B Garlyyev, F Mayr, A S Bandarenka, A Gagliardi Oxygen Reduction Activities of Strained Platinum Core–Shell Electrocatalysts Predicted by Machine Learning Journal Article The Journal of Physical Chemistry Letters, pp. 1773-1780, 2020. Links | Tags: Solid-Liquid @article{, title = {Oxygen Reduction Activities of Strained Platinum Core\textendashShell Electrocatalysts Predicted by Machine Learning}, author = {M R\"{u}ck and B Garlyyev and F Mayr and A S Bandarenka and A Gagliardi}, url = {https://doi.org/10.1021/acs.jpclett.0c00214}, doi = {10.1021/acs.jpclett.0c00214}, year = {2020}, date = {2020-02-14}, journal = {The Journal of Physical Chemistry Letters}, pages = {1773-1780}, keywords = {Solid-Liquid}, pubstate = {published}, tppubtype = {article} } |
| 78. | L Grabenhorst, K Trofymchuk, F Steiner, V Glembockyte, P Tinnefeld Fluorophore photostability and saturation in the hotspot of DNA origami nanoantennas Journal Article Methods and Applications in Fluorescence, 8 (2), pp. 024003, 2020, ISSN: 2050-6120. Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized @article{, title = {Fluorophore photostability and saturation in the hotspot of DNA origami nanoantennas}, author = {L Grabenhorst and K Trofymchuk and F Steiner and V Glembockyte and P Tinnefeld}, url = {http://dx.doi.org/10.1088/2050-6120/ab6ac8}, doi = {10.1088/2050-6120/ab6ac8}, issn = {2050-6120}, year = {2020}, date = {2020-02-05}, journal = {Methods and Applications in Fluorescence}, volume = {8}, number = {2}, pages = {024003}, abstract = {Fluorescent dyes used for single-molecule spectroscopy can undergo millions of excitation-emission cycles before photobleaching. Due to the upconcentration of light in a plasmonic hotspot, the conditions for fluorescent dyes are even more demanding in DNA origami nanoantennas. Here, we briefly review the current state of fluorophore stabilization for single-molecule imaging and reveal additional factors relevant in the context of plasmonic fluorescence enhancement. We show that despite the improved photostability of single-molecule fluorophores by DNA origami nanoantennas, their performance in the intense electric fields in plasmonic hotspots is still limited by the underlying photophysical processes, such as formation of dim states and photoisomerization. These photophysical processes limit the photon count rates, increase heterogeneity and aggravate quantification of fluorescence enhancement factors. These factors also reduce the time resolution that can be achieved in biophysical single-molecule experiments. Finally, we show how the photophysics of a DNA hairpin assay with a fluorophore-quencher pair can be influenced by plasmonic DNA origami nanoantennas leading to implications for their use in fluorescence-based diagnostic assays. Especially, we show that such assays can produce false positive results by premature photobleaching of the dark quencher.}, keywords = {Foundry Organic, Molecularly-Functionalized}, pubstate = {published}, tppubtype = {article} } Fluorescent dyes used for single-molecule spectroscopy can undergo millions of excitation-emission cycles before photobleaching. Due to the upconcentration of light in a plasmonic hotspot, the conditions for fluorescent dyes are even more demanding in DNA origami nanoantennas. Here, we briefly review the current state of fluorophore stabilization for single-molecule imaging and reveal additional factors relevant in the context of plasmonic fluorescence enhancement. We show that despite the improved photostability of single-molecule fluorophores by DNA origami nanoantennas, their performance in the intense electric fields in plasmonic hotspots is still limited by the underlying photophysical processes, such as formation of dim states and photoisomerization. These photophysical processes limit the photon count rates, increase heterogeneity and aggravate quantification of fluorescence enhancement factors. These factors also reduce the time resolution that can be achieved in biophysical single-molecule experiments. Finally, we show how the photophysics of a DNA hairpin assay with a fluorophore-quencher pair can be influenced by plasmonic DNA origami nanoantennas leading to implications for their use in fluorescence-based diagnostic assays. Especially, we show that such assays can produce false positive results by premature photobleaching of the dark quencher. |
| 77. | D Ruhstorfer, S Mejia, M Ramsteiner, M Döblinger, H Riedl, J J Finley, G Koblmüller Demonstration of n-type behavior in catalyst-free Si-doped GaAs nanowires grown by molecular beam epitaxy Journal Article Applied Physics Letters, 116 (5), pp. 052101, 2020. Links | Tags: Foundry Inorganic, Molecularly-Functionalized @article{, title = {Demonstration of n-type behavior in catalyst-free Si-doped GaAs nanowires grown by molecular beam epitaxy}, author = {D Ruhstorfer and S Mejia and M Ramsteiner and M D\"{o}blinger and H Riedl and J J Finley and G Koblm\"{u}ller}, url = {https://aip.scitation.org/doi/abs/10.1063/1.5134687}, doi = {10.1063/1.5134687}, year = {2020}, date = {2020-02-04}, journal = {Applied Physics Letters}, volume = {116}, number = {5}, pages = {052101}, keywords = {Foundry Inorganic, Molecularly-Functionalized}, pubstate = {published}, tppubtype = {article} } |
| 76. | O E O Zeman, Von F O Rohr, L Neudert, W Schnick Facile One-step Synthesis of Zn1-xMnxSiN2 Nitride Semiconductor Solid Solutions via Solid-state Metathesis Reaction Journal Article Zeitschrift Fur Anorganische Und Allgemeine Chemie, 2020, ISSN: 0044-2313. Links | Tags: Foundry Inorganic @article{, title = {Facile One-step Synthesis of Zn1-xMnxSiN2 Nitride Semiconductor Solid Solutions via Solid-state Metathesis Reaction}, author = {O E O Zeman and Von F O Rohr and L Neudert and W Schnick}, url = {<Go to ISI>://WOS:000510472600001}, doi = {10.1002/zaac.201900315}, issn = {0044-2313}, year = {2020}, date = {2020-02-03}, journal = {Zeitschrift Fur Anorganische Und Allgemeine Chemie}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } |
| 75. | M Asher, D Angerer, R Korobko, Y Diskin-Posner, D A Egger, O Yaffe Anharmonic Lattice Vibrations in Small-Molecule Organic Semiconductors Journal Article Advanced Materials, 32 (10), pp. 1908028, 2020, ISSN: 0935-9648. Abstract | Links | Tags: Foundry Organic @article{, title = {Anharmonic Lattice Vibrations in Small-Molecule Organic Semiconductors}, author = {M Asher and D Angerer and R Korobko and Y Diskin-Posner and D A Egger and O Yaffe}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201908028}, doi = {10.1002/adma.201908028}, issn = {0935-9648}, year = {2020}, date = {2020-01-31}, journal = {Advanced Materials}, volume = {32}, number = {10}, pages = {1908028}, abstract = {Abstract The intermolecular lattice vibrations in small-molecule organic semiconductors have a strong impact on their functional properties. Existing models treat the lattice vibrations within the harmonic approximation. In this work, polarization-orientation (PO) Raman measurements are used to monitor the temperature-evolution of the symmetry of lattice vibrations in anthracene and pentacene single crystals. Combined with first-principles calculations, it is shown that at 10 K, the lattice dynamics of the crystals are indeed harmonic. However, as the temperature is increased, specific lattice modes gradually lose their PO dependence and become more liquid-like. This finding is indicative of a dynamic symmetry breaking of the crystal structure and shows clear evidence of the strongly anharmonic nature of these vibrations. Pentacene also shows an apparent phase transition between 80 and 150 K, indicated by a change in the vibrational symmetry of one of the lattice modes. These findings lay the groundwork for accurate predictions of the electronic properties of high-mobility organic semiconductors at room temperature.}, keywords = {Foundry Organic}, pubstate = {published}, tppubtype = {article} } Abstract The intermolecular lattice vibrations in small-molecule organic semiconductors have a strong impact on their functional properties. Existing models treat the lattice vibrations within the harmonic approximation. In this work, polarization-orientation (PO) Raman measurements are used to monitor the temperature-evolution of the symmetry of lattice vibrations in anthracene and pentacene single crystals. Combined with first-principles calculations, it is shown that at 10 K, the lattice dynamics of the crystals are indeed harmonic. However, as the temperature is increased, specific lattice modes gradually lose their PO dependence and become more liquid-like. This finding is indicative of a dynamic symmetry breaking of the crystal structure and shows clear evidence of the strongly anharmonic nature of these vibrations. Pentacene also shows an apparent phase transition between 80 and 150 K, indicated by a change in the vibrational symmetry of one of the lattice modes. These findings lay the groundwork for accurate predictions of the electronic properties of high-mobility organic semiconductors at room temperature. |
| 74. | L Polavarapu, S Paul, E Bladt, A F Richter, M Döblinger, Y Tong, H Huang, A Dey, S Bals, T Debnath, J Feldmann Manganese Doping Induced Quantum Confinement within Host Perovskite Nanocrystals through Ruddlesden-Popper Defects Journal Article Angewandte Chemie International Edition, n/a (n/a), 2020, ISSN: 1433-7851. Abstract | Links | Tags: Foundry Inorganic @article{, title = {Manganese Doping Induced Quantum Confinement within Host Perovskite Nanocrystals through Ruddlesden-Popper Defects}, author = {L Polavarapu and S Paul and E Bladt and A F Richter and M D\"{o}blinger and Y Tong and H Huang and A Dey and S Bals and T Debnath and J Feldmann}, url = {https://doi.org/10.1002/anie.201914473}, doi = {10.1002/anie.201914473}, issn = {1433-7851}, year = {2020}, date = {2020-01-30}, journal = {Angewandte Chemie International Edition}, volume = {n/a}, number = {n/a}, abstract = {The concept of doping Mn 2+ ions into II-VI semiconductor nanocrystals (NCs) has recently extended to perovskite NCs. To date, most studies on Mn 2+ doped NCs focus on enhancing the emission related to the Mn 2 + dopant via an energy transfer mechanism. In this work, we found that the doping of Mn 2+ ions into CsPbCl 3 NCs not only results in a Mn 2+ -related orange emission, but also strongly influences the excitonic properties of the host NCs. We observe for the first time that Mn 2+ doping leads to the formation of Ruddlesden-Popper (R.P.) defects and thus induces quantum confinement within the host NCs. We find that a slight doping with Mn 2+ ions improves the size distribution of the NCs, which results in a prominent excitonic peak. However, with increasing the Mn 2+ concentration, the number of R.P. planes increases leading to smaller single crystal domains. The thus enhanced confinement and crystal inhomogeneity cause a gradual blue shift and broadening of the excitonic transition, respectively.}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } The concept of doping Mn 2+ ions into II-VI semiconductor nanocrystals (NCs) has recently extended to perovskite NCs. To date, most studies on Mn 2+ doped NCs focus on enhancing the emission related to the Mn 2 + dopant via an energy transfer mechanism. In this work, we found that the doping of Mn 2+ ions into CsPbCl 3 NCs not only results in a Mn 2+ -related orange emission, but also strongly influences the excitonic properties of the host NCs. We observe for the first time that Mn 2+ doping leads to the formation of Ruddlesden-Popper (R.P.) defects and thus induces quantum confinement within the host NCs. We find that a slight doping with Mn 2+ ions improves the size distribution of the NCs, which results in a prominent excitonic peak. However, with increasing the Mn 2+ concentration, the number of R.P. planes increases leading to smaller single crystal domains. The thus enhanced confinement and crystal inhomogeneity cause a gradual blue shift and broadening of the excitonic transition, respectively. |
| 73. | T Scholz, F Pielnhofer, R Eger, B V Lotsch Lanthanide orthothiophosphates revisited: single-crystal X-ray, Raman, and DFT studies of TmPS4 and YbPS4 Journal Article Zeitschrift für Naturforschung B, 75 , 2020. Links | Tags: Foundry Inorganic @article{, title = {Lanthanide orthothiophosphates revisited: single-crystal X-ray, Raman, and DFT studies of TmPS4 and YbPS4}, author = {T Scholz and F Pielnhofer and R Eger and B V Lotsch}, doi = {10.1515/znb-2019-0217}, year = {2020}, date = {2020-01-28}, journal = {Zeitschrift f\"{u}r Naturforschung B}, volume = {75}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } |
| 72. | S S Yin, L Song, S L Xia, Y J Cheng, N Hohn, W Chen, K Wang, W Cao, S J Hou, P Muller-Buschbaum Key Factors for Template-Oriented Porous Titania Synthesis: Solvents and Catalysts Journal Article Small Methods, 2020, ISSN: 2366-9608. Links | Tags: Solid-Solid @article{, title = {Key Factors for Template-Oriented Porous Titania Synthesis: Solvents and Catalysts}, author = {S S Yin and L Song and S L Xia and Y J Cheng and N Hohn and W Chen and K Wang and W Cao and S J Hou and P Muller-Buschbaum}, url = {<Go to ISI>://WOS:000507321300001}, doi = {10.1002/smtd.201900689}, issn = {2366-9608}, year = {2020}, date = {2020-01-15}, journal = {Small Methods}, keywords = {Solid-Solid}, pubstate = {published}, tppubtype = {article} } |
| 71. | W J Li, S Xue, S Watzele, S J Hou, J Fichtner, A L Semrau, L J Zhou, A Welle, A S Bandarenka, R A Fischer Advanced Bifunctional Oxygen Reduction and Evolution Electrocatalyst Derived from Surface-Mounted Metal-Organic Frameworks Journal Article Angewandte Chemie-International Edition, 2020, ISSN: 1433-7851. Links | Tags: Molecularly-Functionalized, Solid-Liquid @article{, title = {Advanced Bifunctional Oxygen Reduction and Evolution Electrocatalyst Derived from Surface-Mounted Metal-Organic Frameworks}, author = {W J Li and S Xue and S Watzele and S J Hou and J Fichtner and A L Semrau and L J Zhou and A Welle and A S Bandarenka and R A Fischer}, url = {<Go to ISI>://WOS:000509752400001}, doi = {10.1002/anie.201916507}, issn = {1433-7851}, year = {2020}, date = {2020-01-08}, journal = {Angewandte Chemie-International Edition}, keywords = {Molecularly-Functionalized, Solid-Liquid}, pubstate = {published}, tppubtype = {article} } |
| 70. | C Heshmatpour, J Hauer, F Sanda Interplay of exciton annihilation and transport in fifth order electronic spectroscopy Journal Article Chemical Physics, 528 , 2020, ISSN: 0301-0104. Links | Tags: Molecularly-Functionalized, Solid-Liquid @article{, title = {Interplay of exciton annihilation and transport in fifth order electronic spectroscopy}, author = {C Heshmatpour and J Hauer and F Sanda}, url = {<Go to ISI>://WOS:000490758300009}, doi = {10.1016/j.chemphys.2019.110433}, issn = {0301-0104}, year = {2020}, date = {2020-01-01}, journal = {Chemical Physics}, volume = {528}, keywords = {Molecularly-Functionalized, Solid-Liquid}, pubstate = {published}, tppubtype = {article} } |
| 69. | M Däntl, P Ganter, K Szendrei-Temesi, A Jiménez-Solano, B V Lotsch Customizing H3Sb3P2O14 nanosheet sensors by reversible vapor-phase amine intercalation Journal Article Nanoscale Horizons, 5 (1), pp. 74-81, 2020, ISSN: 2055-6756. Abstract | Links | Tags: Foundry Inorganic @article{, title = {Customizing H3Sb3P2O14 nanosheet sensors by reversible vapor-phase amine intercalation}, author = {M D\"{a}ntl and P Ganter and K Szendrei-Temesi and A Jim\'{e}nez-Solano and B V Lotsch}, url = {http://dx.doi.org/10.1039/C9NH00434C}, doi = {10.1039/C9NH00434C}, issn = {2055-6756}, year = {2020}, date = {2020-01-01}, journal = {Nanoscale Horizons}, volume = {5}, number = {1}, pages = {74-81}, abstract = {Harvesting the large property space of 2D materials and their molecular-level fine-tuning is of utmost importance for future applications such as miniaturized sensors for environmental monitoring or biomedical detection. Therefore, developing straightforward strategies for the reversible and gradual fine-tuning of nanosheet properties with soft chemical intercalation methods is in high demand. Herein we address this challenge by customizing the host\textendashguest interactions of nanosheets based on the solid acid H3Sb3P2O14 by vapor-phase amine-intercalation with primary alkylamines. Fine-tuning of the structural and chemical properties of the intercalated nanosheets is achieved by applying a two-step, post-synthetic intercalation strategy via the vapor phase. The method allows for the gradual and reversible replacement of one amine type by another. Hence, fine-tuning of the d-spacing in the sub-r{A} regime is accomplished and offers exquisite control of the properties of the thin films such as refractive index, polarity, film thickness and sensitivity towards solvent vapors. Moreover, we employ amine replacement to pattern thin films by locally resolved amine intercalation and subsequent washing, leading to spatially dependent property profiles. This process thus adds a new vapor-phase, amine-based variant to the toolbox of soft lithography.}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } Harvesting the large property space of 2D materials and their molecular-level fine-tuning is of utmost importance for future applications such as miniaturized sensors for environmental monitoring or biomedical detection. Therefore, developing straightforward strategies for the reversible and gradual fine-tuning of nanosheet properties with soft chemical intercalation methods is in high demand. Herein we address this challenge by customizing the host–guest interactions of nanosheets based on the solid acid H3Sb3P2O14 by vapor-phase amine-intercalation with primary alkylamines. Fine-tuning of the structural and chemical properties of the intercalated nanosheets is achieved by applying a two-step, post-synthetic intercalation strategy via the vapor phase. The method allows for the gradual and reversible replacement of one amine type by another. Hence, fine-tuning of the d-spacing in the sub-Å regime is accomplished and offers exquisite control of the properties of the thin films such as refractive index, polarity, film thickness and sensitivity towards solvent vapors. Moreover, we employ amine replacement to pattern thin films by locally resolved amine intercalation and subsequent washing, leading to spatially dependent property profiles. This process thus adds a new vapor-phase, amine-based variant to the toolbox of soft lithography. |
| 68. | J Klein, A Kerelsky, M Lorke, M Florian, F Sigger, J Kiemle, M C Reuter, T Taniguchi, K Watanabe, J J Finley, A N Pasupathy, A W Holleitner, F M Ross, U Wurstbauer Impact of substrate induced band tail states on the electronic and optical properties of MoS2 Journal Article Applied Physics Letters, 115 (26), 2019, ISSN: 0003-6951. Links | Tags: Foundry Inorganic @article{, title = {Impact of substrate induced band tail states on the electronic and optical properties of MoS2}, author = {J Klein and A Kerelsky and M Lorke and M Florian and F Sigger and J Kiemle and M C Reuter and T Taniguchi and K Watanabe and J J Finley and A N Pasupathy and A W Holleitner and F M Ross and U Wurstbauer}, url = {<Go to ISI>://WOS:000505613600019}, doi = {10.1063/1.5131270}, issn = {0003-6951}, year = {2019}, date = {2019-12-30}, journal = {Applied Physics Letters}, volume = {115}, number = {26}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } |
| 67. | A Haffner, A K Hatz, C Hoch, B V Lotsch, D Johrendt Synthesis and Structure of the Sodium Phosphidosilicate Na2SiP2 Journal Article European Journal of Inorganic Chemistry, 2019, ISSN: 1434-1948. Links | Tags: Foundry Inorganic @article{, title = {Synthesis and Structure of the Sodium Phosphidosilicate Na2SiP2}, author = {A Haffner and A K Hatz and C Hoch and B V Lotsch and D Johrendt}, url = {<Go to ISI>://WOS:000511390500001}, doi = {10.1002/ejic.201901083}, issn = {1434-1948}, year = {2019}, date = {2019-12-29}, journal = {European Journal of Inorganic Chemistry}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } |
| 66. | A M Ferrenti, S Klemenz, S M Lei, X Y Song, P Ganter, B V Lotsch, L M Schoop Change in Magnetic Properties upon Chemical Exfoliation of FeOCl Journal Article Inorganic Chemistry, 59 (2), pp. 1176-1182, 2019, ISSN: 0020-1669. Links | Tags: Foundry Inorganic @article{, title = {Change in Magnetic Properties upon Chemical Exfoliation of FeOCl}, author = {A M Ferrenti and S Klemenz and S M Lei and X Y Song and P Ganter and B V Lotsch and L M Schoop}, url = {<Go to ISI>://WOS:000509420100027}, doi = {10.1021/acs.inorgchem.9b02856}, issn = {0020-1669}, year = {2019}, date = {2019-12-27}, journal = {Inorganic Chemistry}, volume = {59}, number = {2}, pages = {1176-1182}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } |
| 65. | J Schedlbauer, P Wilhelm, L Grabenhorst, M E Federl, B Lalkens, F Hinderer, U Scherf, S Höger, P Tinnefeld, S Bange, J Vogelsang, J M Lupton Ultrafast Single-Molecule Fluorescence Measured by Femtosecond Double-Pulse Excitation Photon Antibunching Journal Article Nano Letters, 2019, ISSN: 1530-6984. Links | Tags: Foundry Organic, Molecularly-Functionalized @article{, title = {Ultrafast Single-Molecule Fluorescence Measured by Femtosecond Double-Pulse Excitation Photon Antibunching}, author = {J Schedlbauer and P Wilhelm and L Grabenhorst and M E Federl and B Lalkens and F Hinderer and U Scherf and S H\"{o}ger and P Tinnefeld and S Bange and J Vogelsang and J M Lupton}, url = {https://doi.org/10.1021/acs.nanolett.9b04354}, doi = {10.1021/acs.nanolett.9b04354}, issn = {1530-6984}, year = {2019}, date = {2019-12-23}, journal = {Nano Letters}, keywords = {Foundry Organic, Molecularly-Functionalized}, pubstate = {published}, tppubtype = {article} } |
| 64. | S Zhang, L Diehl, S Wrede, B V Lotsch, C Scheu Structural Evolution of Ni-Based Co-Catalysts on [Ca2Nb3O10]− Nanosheets during Heating and Their Photocatalytic Properties Journal Article Catalysts, 10 (1), pp. 13, 2019, ISSN: 2073-4344. Links | Tags: Foundry Inorganic @article{, title = {Structural Evolution of Ni-Based Co-Catalysts on [Ca2Nb3O10]− Nanosheets during Heating and Their Photocatalytic Properties}, author = {S Zhang and L Diehl and S Wrede and B V Lotsch and C Scheu}, url = {https://www.mdpi.com/2073-4344/10/1/13}, issn = {2073-4344}, year = {2019}, date = {2019-12-20}, journal = {Catalysts}, volume = {10}, number = {1}, pages = {13}, keywords = {Foundry Inorganic}, pubstate = {published}, tppubtype = {article} } |
Publications2020-08-21T17:11:33+02:00