Publications

@article{,

title = {Determination of Electroactive Surface Area of Ni-, Co-, Fe-, and Ir-Based Oxide Electrocatalysts},

author = {S Watzele and P Hauenstein and Y C Liang and S Xue and J Fichtner and B Garlyyev and D Scieszka and F Claude and F Maillard and A S Bandarenka},

url = {\<Go to ISI\>://WOS:000489204000043},

doi = {10.1021/acscatal.9b02006},

issn = {2155-5435},

year  = {2019},

date = {2019-08-30},

journal = {Acs Catalysis},

volume = {9},

number = {10},

pages = {9222-9230},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Preparation of Polyfunctional Biaryl Derivatives by Cyclolanthanation of 2-Bromobiaryls and Heterocyclic Analogues Using nBu(2)LaCl.4 LiCl},

author = {B S Wei and D C Zhang and Y H Chen and A W Lei and P Knochel},

url = {\<Go to ISI\>://WOS:000487102700001},

doi = {10.1002/anie.201908046},

issn = {1433-7851},

year  = {2019},

date = {2019-08-28},

journal = {Angewandte Chemie-International Edition},

volume = {58},

number = {44},

pages = {15631-15635},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Ultrafast All-Optical Modulation in 2D Hybrid Perovskites},

author = {G Grinblat and I Abdelwahab and M P Nielsen and P Dichtl and K Leng and R F Oulton and K P Loh and S A Maier},

url = {https://doi.org/10.1021/acsnano.9b04483},

doi = {10.1021/acsnano.9b04483},

issn = {1936-0851},

year  = {2019},

date = {2019-08-27},

journal = {ACS Nano},

volume = {13},

number = {8},

pages = {9504-9510},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Introducing catalysis in photocatalysis: What can be understood from surface science studies of alcohol photoreforming on TiO2},

author = {C A Walenta and M Tschurl and U Heiz},

url = {\<Go to ISI\>://WOS:000482603900001},

doi = {10.1088/1361-648X/ab351a},

issn = {0953-8984},

year  = {2019},

date = {2019-08-23},

urldate = {2019-08-23},

journal = {Journal of Physics-Condensed Matter},

volume = {31},

number = {47},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Spontaneous Crystallization of Perovskite Nanocrystals in Nonpolar Organic Solvents: A Versatile Approach for their Shape-controlled Synthesis},

author = {L Polavarapu and H Huang and Y Li and Y Tong and E-P Yao and M D\"{o}blinger and M W Feil and A F Richter and A L Rogach and J Feldmann},

url = {https://doi.org/10.1002/anie.201906862},

doi = {10.1002/anie.201906862},

issn = {1433-7851},

year  = {2019},

date = {2019-08-21},

journal = {Angewandte Chemie International Edition},

volume = {0},

number = {ja},

abstract = {The growing demand of perovskite nanocrystals (NCs) for various applications has stimulated great research interest in the development of facile synthetic methods. They have often been synthesized by either ligand assisted reprecipitation (LARP) at room temperature or by hot-injection at high temperatures and inert atmosphere. However, the use of polar solvents in LARP effects their stability. Herein, we report on the spontaneous crystallization of perovskite nanocrystals in nonpolar organic media at ambient conditions by simple mixing of precursor-ligand complexes without applying any external stimuli. The shape of the NCs can be controlled from nanocubes to nanoplatelets by varying the ratio of monovalent (e.g. formamidinium+ (FA+) and Cs+) to divalent (Pb2+) cation-ligand complexes. The precursor-ligand complexes are stable for months, and thus perovskite NCs can be readily prepared prior to use.  Moreover, we show that this versatile synthetic process is scalable and can be generally applicable for perovskite NCs of different compositions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Recent Approaches to Design Electrocatalysts Based on Metal\textendashOrganic Frameworks and Their Derivatives},

author = {J Liu and S Hou and W Li and A S Bandarenka and R A Fischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/asia.201900748},

doi = {https://doi.org/10.1002/asia.201900748},

issn = {1861-4728},

year  = {2019},

date = {2019-08-20},

journal = {Chemistry \textendash An Asian Journal},

volume = {14},

number = {20},

pages = {3474-3501},

abstract = {Abstract Rational design and synthesis of efficient electrocatalysts are important constituents in addressing the currently growing provision issues. Typical reactions, which are important to catalyze in this respect, include CO2 reduction, the hydrogen and oxygen evolution reactions as well as the oxygen reduction reaction. The most efficient catalysts known up-to-date for these processes usually contain expensive and scarce elements, substantially impeding implementation of such electrocatalysts at a larger scale. Metal-organic frameworks (MOFs) and their derivatives containing affordable components and building blocks, as an emerging class of porous functional materials, have been recently attracting a great attention thanks to their tunable structure and composition together with high surface area, just to name a few. Up to now, several MOFs and MOF-derivatives have been reported as electrode materials for the energy-related electrocatalytic application. In this review article, we summarize and analyze current approaches to design such materials. The design strategies to improve the Faradaic efficiency and selectivity of these catalysts are discussed. Last but not least, we discuss some novel strategies to enhance the conductivity, chemical stability and efficiency of MOF-derived electrocatalysts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {From Optical to Chemical Hot Spots in Plasmonics},

author = {J Gargiulo and R Bert\'{e} and Y Li and S A Maier and E Cort\'{e}s},

url = {https://doi.org/10.1021/acs.accounts.9b00234},

doi = {10.1021/acs.accounts.9b00234},

issn = {0001-4842},

year  = {2019},

date = {2019-08-20},

journal = {Accounts of Chemical Research},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {A Cell for Controllable Formation and In Operando Electrochemical Characterization of Intercalation Materials for Aqueous Metal-Ion Batteries},

author = {P Marzak and P Moser and S Schreier and D Scieszka and J Yun and O Schneider and A S Bandarenka},

url = {\<Go to ISI\>://WOS:000481312300001},

doi = {10.1002/smtd.201900445},

issn = {2366-9608},

year  = {2019},

date = {2019-08-16},

urldate = {2019-08-16},

journal = {Small Methods},

volume = {3},

pages = {1900445},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Nonlinear Pancharatnam−Berry Phase Metasurfaces beyond the Dipole Approximation},

author = {S D Gennaro and Y Li and S A Maier and R F Oulton},

url = {https://doi.org/10.1021/acsphotonics.9b00877},

doi = {10.1021/acsphotonics.9b00877},

year  = {2019},

date = {2019-08-12},

journal = {ACS Photonics},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Structural Insights into Poly(Heptazine Imides): A Light Storing Carbon Nitride Material for Dark Photocatalysis},

author = {H Schlomberg and J Kr\"{o}ger and G Savasci and M Terban and S Bette and I Moudrakovski and V Duppel and F Podjaski and R Siegel and J Senker and R Dinnebier and C Ochsenfeld and B V Lotsch},

doi = {10.1021/acs.chemmater.9b02199},

year  = {2019},

date = {2019-08-12},

journal = {Chemistry of Materials},

volume = {31},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Generation and Stabilization of Small Platinum Clusters Pt-12 +/- x Inside a Metal-Organic Framework},

author = {K Kratzl and T Kratky and S Gunther and O Tomanec and R Zboril and J Michalicka and J M Macak and M Cokoja and R A Fischer},

url = {\<Go to ISI\>://WOS:000484828900039},

doi = {10.1021/jacs.9b07083},

issn = {0002-7863},

year  = {2019},

date = {2019-08-09},

journal = {Journal of the American Chemical Society},

volume = {141},

number = {35},

pages = {13962-13969},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Ultrawideband Surface Enhanced Raman Scattering in Hybrid Graphene Fragmented-Gold Substrates via Cold-Etching},

author = {T Wu and K Li and N Zhang and J Xia and Q Zeng and X Wen and U S Dinish and M Olivo and Z Shen and Z Liu and Q Xiong and Y Luo and S A Maier and L Wei},

url = {https://doi.org/10.1002/adom.201900905},

doi = {10.1002/adom.201900905},

issn = {2195-1071},

year  = {2019},

date = {2019-08-08},

journal = {Advanced Optical Materials},

volume = {0},

number = {0},

pages = {1900905},

abstract = {Abstract Conventional surface enhanced Raman scattering (SERS) substrates are well known for their supreme electromagnetic enhancements and ultrahigh sensitivity in detecting molecules at low concentrations. However, large-area quasi-uniform SERS substrates are difficult to achieve by standard top-down nanofabrication techniques, resulting in fluctuant SERS responses and unwanted fluorescence interferences, which severely limit their performances in practical applications. To tackle these challenges, a large-scale quasi-uniform hybrid graphene fragmented-gold substrate with stable and reproducible SERS readouts as well as large enhancement factors over an ultrawideband spectrum is developed. The hybrid substrate is fabricated via cold-etching through a controllable break up of a thin gold film followed by a graphene transfer. The stimulated localized surface plasmons interact strongly with the graphene layer, leading to spectrally and spatially modified graphene-mediated surface enhanced Raman scattering (GSERS) responses. The perfect monolayer graphene of the GSERS substrate prevents adsorbates from the atmosphere and direct contact between bonded molecules and gold, thus reducing the catalytic activity of gold and producing clean, stable, and reproducible molecular Raman signals. The easy-fabricated hybrid GSERS substrate not only provides a powerful platform to collect robust molecular Raman spectra but also shows great potentials for future mass production of high-performance nanophotonic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Reactions in the Photocatalytic Conversion of Tertiary Alcohols on Rutile TiO2(110)},

author = {C Courtois and M Eder and K Schnabl and C A Walenta and M Tschurl and U Heiz},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201907917},

doi = {https://doi.org/10.1002/anie.201907917},

issn = {1433-7851},

year  = {2019},

date = {2019-08-07},

journal = {Angewandte Chemie International Edition},

volume = {58},

number = {40},

pages = {14255-14259},

abstract = {Abstract According to textbooks, tertiary alcohols are inert towards oxidation. The photocatalysis of tertiary alcohols under highly defined vacuum conditions on a titania single crystal reveals unexpected and new reactions, which can be described as disproportionation into an alkane and the respective ketone. In contrast to primary and secondary alcohols, in tertiary alcohols the absence of an α-H leads to a C−C-bond cleavage instead of the common abstraction of hydrogen. Surprisingly, bonds to methyl groups are not cleaved when the alcohol exhibits longer alkyl chains in the α-position to the hydroxyl group. The presence of platinum loadings not only increases the reaction rate but also opens up a new reaction channel: the formation of molecular hydrogen and a long-chain alkane resulting from recombination of two alkyl moieties. This work demonstrates that new synthetic routes may become possible by introducing photocatalytic reaction steps in which the co-catalysts may also play a decisive role.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Highly Selective Pt/TiOx Catalysts for the Hydrogen Oxidation Reaction},

author = {B M St\"{u}hmeier and S Selve and M U M Patel and T N Geppert and H A Gasteiger and H A El-Sayed},

url = {https://doi.org/10.1021/acsaem.9b00718},

doi = {10.1021/acsaem.9b00718},

year  = {2019},

date = {2019-08-05},

journal = {ACS Applied Energy Materials},

volume = {2},

number = {8},

pages = {5534-5539},

abstract = {Reducing the cathode degradation in proton exchange membrane fuel cells during start-up and shut-down events (where the anode is filled with H2 and air) is crucial for its widespread automotive implementation. The use of selective catalysts for the hydrogen oxidation reaction (HOR) that sparingly reduce oxygen on the anode could significantly reduce the carbon corrosion on the cathode. Herein, we report a novel system of carbon supported Pt/TiOx catalysts that combines the unique properties of a strong metal\textendashsupport interaction (SMSI) with the known advantages of a carbon support. High-resolution transmission electron microscopy of the selective catalyst shows the encapsulation of the Pt nanoparticles (NPs) by a TiOx layer resulting from the SMSI. Rotating disk electrode experiments confirmed that Pt oxidation and oxygen reduction are hindered due to the TiOx layer. Furthermore, a high HOR activity that is retained even at high potentials proved the superior HOR selectivity of the catalyst.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Low-Scaling Self-Consistent Minimization of a Density Matrix Based Random Phase Approximation Method in the Atomic Orbital Space},

author = {D Graf and M Beuerle and C Ochsenfeld},

url = {\<Go to ISI\>://WOS:000480826800016},

doi = {10.1021/acs.jctc.9b00444},

issn = {1549-9618},

year  = {2019},

date = {2019-08-01},

journal = {Journal of Chemical Theory and Computation},

volume = {15},

number = {8},

pages = {4468-4477},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Ultracompact Photodetection in Atomically Thin MoSe2},

author = {M Blauth and G Vest and S L Rosemary and M Prechtl and O Hartwig and M Jurgensen and M Kaniber and A V Stier and J J Finley},

url = {\<Go to ISI\>://WOS:000482545400012},

doi = {10.1021/acsphotonics.9b00785},

issn = {2330-4022},

year  = {2019},

date = {2019-07-30},

journal = {Acs Photonics},

volume = {6},

number = {8},

pages = {1902-1909},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Revealing the nature of active sites in electrocatalysis},

author = {B Garlyyev and J Fichtner and O Pique and O Schneider and A S Bandarenka and F Calle-Vallejo},

url = {\<Go to ISI\>://WOS:000486045200001},

doi = {10.1039/c9sc02654a},

issn = {2041-6520},

year  = {2019},

date = {2019-07-23},

journal = {Chemical Science},

volume = {10},

number = {35},

pages = {8060-8075},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Polymer Nanoreactors Shield Perovskite Nanocrystals from Degradation},

author = {V A Hintermayr and C Lampe and M Low and J Roemer and W Vanderlinden and M Gramlich and A X Bohm and C Sattler and B Nickel and T Lohmuller and A S Urban},

url = {\<Go to ISI\>://WOS:000481563800015},

doi = {10.1021/acs.nanolett.9b00982},

issn = {1530-6984},

year  = {2019},

date = {2019-07-19},

journal = {Nano Letters},

volume = {19},

number = {8},

pages = {4928-4933},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Coupled Dynamics of Anode and Cathode in Proton-Exchange Membrane Fuel Cells},

author = {J A Nogueira and K Krischer and H Varela},

url = {\<Go to ISI\>://WOS:000478934200001},

doi = {10.1002/cphc.201900531},

issn = {1439-4235},

year  = {2019},

date = {2019-07-19},

journal = {Chemphyschem},

volume = {20},

number = {22},

pages = {3081-3088},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {The fast and the furious: Ultrafast hot electrons in plasmonic metastructures. Size and structure matter},

author = {L V Besteiro and P Yu and Z M Wang and A W Holleitner and G V Hartland and G P Wiederrecht and A O Govorov},

url = {\<Go to ISI\>://WOS:000482526300011},

doi = {10.1016/j.nantod.2019.05.006},

issn = {1748-0132},

year  = {2019},

date = {2019-07-18},

journal = {Nano Today},

volume = {27},

pages = {120-145},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Influence of Local Defects on the Dynamics of O-H Bond Breaking and Formation on a Magnetite Surface},

author = {A Bourgund and B A J Lechner and M Meier and C Franchini and G S Parkinson and U Heiz and F Esch},

url = {\<Go to ISI\>://WOS:000481568900054},

doi = {10.1021/acs.jpcc.9b05547},

issn = {1932-7447},

year  = {2019},

date = {2019-07-17},

urldate = {2019-07-17},

journal = {Journal of Physical Chemistry C},

volume = {123},

number = {32},

pages = {19742-19747},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {In-situ visualization of hydrogen evolution sites on helium ion treated molybdenum dichalcogenides under reaction conditions},

author = {E Mitterreiter and Y Liang and M Golibrzuch and D Mclaughlin and C Csoklich and J D Bartl and A W Holleitner and U Wurstbauer and A S Bandarenka},

url = {https://doi.org/10.1038/s41699-019-0107-5},

doi = {10.1038/s41699-019-0107-5},

issn = {2397-7132},

year  = {2019},

date = {2019-07-15},

journal = {npj 2D Materials and Applications},

volume = {3},

number = {1},

pages = {25},

abstract = {Nanostructured 2D transition metal dichalcogenides play an increasingly important role in heterogeneous catalysis. These materials are abundant (co-)catalysts with tunable properties to catalyze a number of key reactions related to energy provision, for instance the hydrogen evolution reaction (HER). It is vital to understand which surface sites are active in order to maximize their number and to improve the overall (photo-)catalytic behavior of those materials. Here, we visualize these active sites under HER conditions at the surface of molybdenum dichalcogenides (MoX2, X = Se, S) with lateral resolution on the nanometer scale by means of electrochemical scanning tunneling microscopy. The edges of single MoX2 flakes show high catalytic activity, whereas their terraces are inactive. We demonstrate how the inert basal planes of these materials can be activated towards the HER with the help of a focused beam of a He-ion microscope. Our findings demonstrate that the He-ion induced defects contribute at lower overpotentials to the HER, while the activity of the edges exceeds the activity of the basal defects for sufficiently high overpotentials. Given the lithographic resolution of the helium ion microscope, our results show the possibility to generate active sites in transition metal dichalcogenides with a spatial resolution below a few nanometers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Using Polar Alcohols for the Direct Synthesis of Cesium Lead Halide Perovskite Nanorods with Anisotropic Emission},

author = {Y X Li and H Huang and Y Xiong and A F Richter and S V Kershaw and J Feldmann and A L Rogach},

url = {\<Go to ISI\>://WOS:000477786400088},

doi = {10.1021/acsnano.9b03508},

issn = {1936-0851},

year  = {2019},

date = {2019-07-11},

journal = {Acs Nano},

volume = {13},

number = {7},

pages = {8237-8245},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Distance Dependence of Single-Molecule Energy Transfer to Graphene Measured with DNA Origami Nanopositioners},

author = {I Kaminska and J Bohlen and S Rocchetti and F Selbach and G P Acuna and P Tinnefeld},

url = {https://doi.org/10.1021/acs.nanolett.9b00172},

doi = {10.1021/acs.nanolett.9b00172},

issn = {1530-6984},

year  = {2019},

date = {2019-07-10},

journal = {Nano Letters},

volume = {19},

number = {7},

pages = {4257-4262},

abstract = {Despite the thorough investigation of graphene since 2004, altering its surface chemistry and reproducible functionalization remain challenging. This hinders fabrication of more complex hybrid materials with controlled architectures, and as a consequence the development of sensitive and reliable sensors and biological assays. In this contribution, we introduce DNA origami structures as nanopositioners for placing single dye molecules at controlled distances from graphene. The measurements of fluorescence intensity and lifetime of single emitters carried out for distances ranging from 3 to 58 nm confirmed the d\textendash4 dependence of the excitation energy transfer to graphene. Moreover, we determined the characteristic distance for 50% efficiency of the energy transfer from single dyes to graphene to be 17.7 nm. Using pyrene molecules as a glue to immobilize DNA origami nanostructures of various shape on graphene opens new possibilities to develop graphene-based biophysics and biosensing.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Degradation mechanisms in polymer electrolyte membrane fuel cells caused by freeze-cycles: Investigation using electrochemical impedance spectroscopy},

author = {J P Sabawa and A S Bandarenka},

url = {http://www.sciencedirect.com/science/article/pii/S0013468619307881},

doi = {https://doi.org/10.1016/j.electacta.2019.04.102},

issn = {0013-4686},

year  = {2019},

date = {2019-07-10},

journal = {Electrochimica Acta},

volume = {311},

pages = {21-29},

abstract = {The performance of the polymer electrolyte membrane (PEM) fuel cells is sensitive to the exposure of these devices to subzero temperatures. In general, it is important to precondition the fuel cells prior to the shut-down preventing degradation after the start-up. Standard tests with conventional climatic chambers are nowadays costly and very time consuming. In this work, we introduce a method, which uses a simplified process with a PEM single-cell. The new design uses a Peltier-Element-Tempered (PET) single-cell with an active area size of 43.56 cm2. Now it is possible to achieve efficient and temperature controlled cold starts without a climate chamber or chiller plant. With the PET-controlled single cell, it was possible to do a series of complex accelerated freeze stress tests within the shortest time. To classify the performance change, polarization curves, cyclic voltammetry with the CV-CO-stripping method and Electrochemical Impedance Spectroscopy (EIS) at different current densities were performed. The measured impedance spectra were analyzed with a physical impedance model consisting of only 6 equivalent circuit elements. The charge-transfer resistance and the parameters of the Warburg diffusion element clearly reveal irreversible changes of the cathode during repeated freeze-cycles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Aspects of semiconductivity in soft, porous metal-organic framework crystals},

author = {C Muschielok and H Oberhofer},

url = {\<Go to ISI\>://WOS:000474214600025},

doi = {10.1063/1.5108995},

issn = {0021-9606},

year  = {2019},

date = {2019-07-03},

journal = {Journal of Chemical Physics},

volume = {151},

number = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Site-selectively generated photon emitters in monolayer MoS2 via local helium ion irradiation},

author = {J Klein and M Lorke and M Florian and F Sigger and L Sigl and S Rey and J Wierzbowski and J Cerne and K M\"{u}ller and E Mitterreiter and P Zimmermann and T Taniguchi and K Watanabe and U Wurstbauer and M Kaniber and M Knap and R Schmidt and J J Finley and A W Holleitner},

url = {https://doi.org/10.1038/s41467-019-10632-z},

doi = {10.1038/s41467-019-10632-z},

issn = {2041-1723},

year  = {2019},

date = {2019-06-21},

journal = {Nature Communications},

volume = {10},

number = {1},

pages = {2755},

abstract = {Quantum light sources in solid-state systems are of major interest as a basic ingredient for integrated quantum photonic technologies. The ability to tailor quantum emitters via site-selective defect engineering is essential for realizing scalable architectures. However, a major difficulty is that defects need to be controllably positioned within the material. Here, we overcome this challenge by controllably irradiating monolayer MoS2 using a sub-nm focused helium ion beam to deterministically create defects. Subsequent encapsulation of the ion exposed MoS2 flake with high-quality hBN reveals spectrally narrow emission lines that produce photons in the visible spectral range. Based on ab-initio calculations we interpret these emission lines as stemming from the recombination of highly localized electron\textendashhole complexes at defect states generated by the local helium ion exposure. Our approach to deterministically write optically active defect states in a single transition metal dichalcogenide layer provides a platform for realizing exotic many-body systems, including coupled single-photon sources and interacting exciton lattices that may allow the exploration of Hubbard physics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Sustained Solar H-2 Evolution from a Thiazolo 5,4-d thiazole-Bridged Covalent Organic Framework and Nickel-Thiolate Cluster in Water},

author = {B P Biswal and H A Vignolo-Gonzalez and T Banerjee and L Grunenberg and G Savasci and K Gottschling and J Nuss and C Ochsenfeld and B V Lotsch},

url = {\<Go to ISI\>://WOS:000476684700023},

doi = {10.1021/jacs.9b03243},

issn = {0002-7863},

year  = {2019},

date = {2019-06-20},

journal = {Journal of the American Chemical Society},

volume = {141},

number = {28},

pages = {11082-11092},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Sub-stoichiometric 2D covalent organic frameworks from tri- and tetratopic linkers},

author = {T Banerjee and F Haase and S Trenker and B P Biswal and G Savasci and V Duppel and I Moudrakovski and C Ochsenfeld and B V Lotsch},

url = {\<Go to ISI\>://WOS:000472032300004},

doi = {10.1038/s41467-019-10574-6},

issn = {2041-1723},

year  = {2019},

date = {2019-06-19},

journal = {Nature Communications},

volume = {10},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Temperature-Dependent Ambipolar Charge Carrier Mobility in Large-Crystal Hybrid Halide Perovskite Thin Films},

author = {A Biewald and N Giesbrecht and T Bein and P Docampo and A Hartschuh and R Ciesielski},

url = {https://doi.org/10.1021/acsami.9b04592},

doi = {10.1021/acsami.9b04592},

issn = {1944-8244},

year  = {2019},

date = {2019-06-12},

journal = {ACS Applied Materials \& Interfaces},

volume = {11},

number = {23},

pages = {20838-20844},

abstract = {Perovskite-based thin-film solar cells today reach power conversion efficiencies of more than 22%. Methylammonium lead iodide (MAPI) is prototypical for this material class of hybrid halide perovskite semiconductors and at the focal point of interest for a growing community in research and engineering. Here, a detailed understanding of the charge carrier transport and its limitations by underlying scattering mechanisms is of great interest to the material’s optimization and development. In this article, we present an all-optical study of the charge carrier diffusion properties in large-crystal MAPI thin films in the tetragonal crystal phase from 170 K to room temperature. We probe the local material properties of individual crystal grains within a MAPI thin film and find a steady decrease of the charge carrier diffusion constant with increasing temperature. From the resulting charge carrier mobility, we find a power law dependence of μ ∝ Tm with m = −(1.8 ± 0.1). We further study the temperature-dependent mobility of the orthorhombic crystal phase from 50 to 140 K and observe a distinctly different exponent of m = −(1.2 ± 0.1).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Hydrophobic Metal\textendashOrganic Frameworks},

author = {K Jayaramulu and F Geyer and A Schneemann and \v{S} Kment and M Otyepka and R Zboril and D Vollmer and R A Fischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201900820},

doi = {https://doi.org/10.1002/adma.201900820},

issn = {0935-9648},

year  = {2019},

date = {2019-06-03},

journal = {Advanced Materials},

volume = {31},

number = {32},

pages = {1900820},

abstract = {Abstract Metal\textendashorganic frameworks (MOFs) have diverse potential applications in catalysis, gas storage, separation, and drug delivery because of their nanoscale periodicity, permanent porosity, channel functionalization, and structural diversity. Despite these promising properties, the inherent structural features of even some of the best-performing MOFs make them moisture-sensitive and unstable in aqueous media, limiting their practical usefulness. This problem could be overcome by developing stable hydrophobic MOFs whose chemical composition is tuned to ensure that their metal\textendashligand bonds persist even in the presence of moisture and water. However, the design and fabrication of such hydrophobic MOFs pose a significant challenge. Reported syntheses of hydrophobic MOFs are critically summarized, highlighting issues relating to their design, characterization, and practical use. First, wetting of hydrophobic materials is introduced and the four main strategies for synthesizing hydrophobic MOFs are discussed. Afterward, critical challenges in quantifying the wettability of these hydrophobic porous surfaces and solutions to these challenges are discussed. Finally, the reported uses of hydrophobic MOFs in practical applications such as hydrocarbon storage/separation and their use in separating oil spills from water are summarized. Finally, the state of the art is summarized and promising future developments of hydrophobic MOFs are highlighted.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Short-Range Structural Correlations in Amorphous 2D Polymers},

author = {P Alexa and C Oligschleger and P Gr\"{o}ger and C Morchutt and V Vyas and B V Lotsch and J C Sch\"{o}n and R Gutzler and K Kern},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/cphc.201900326},

doi = {10.1002/cphc.201900326},

issn = {1439-4235},

year  = {2019},

date = {2019-05-21},

journal = {ChemPhysChem},

volume = {20},

number = {18},

pages = {2340-2347},

abstract = {Abstract Many 2D covalent polymers synthesized as single layers on surfaces show inherent disorder, expressed for example in their ring-size distribution. Systems which are expected to form the thermodynamically favored hexagonal lattice usually deviate from crystallinity and include high numbers of pentagons, heptagons, and rings of other sizes. The amorphous structure of two different covalent polymers in real space using scanning tunneling microscopy is investigated. Molecular dynamics simulations are employed to extract additional information. We show that short-range correlations exist in the structure of one polymer, i. e. that polygons are not tessellating the surface randomly but that ring neighborhoods have preferential compositions. The correlation is dictated by the energy of formation of the ring neighborhoods.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Cu9.1Te4Cl3: A Thermoelectric Compound with Low Thermal and High Electrical Conductivity},

author = {A Vogel and T Miller and C Hoch and M Jakob and O Oeckler and T Nilges},

url = {https://doi.org/10.1021/acs.inorgchem.9b00453},

doi = {10.1021/acs.inorgchem.9b00453},

issn = {0020-1669},

year  = {2019},

date = {2019-05-06},

journal = {Inorganic Chemistry},

volume = {58},

number = {9},

pages = {6222-6230},

abstract = {Cu9.1Te4Cl3 is a new polymorphic compound in the class of coinage metal polytelluride halides. Copper is highly mobile, which results in multiple order\textendashdisorder phase transitions in a limited temperature interval from 240 to 370 K. Mainly as a consequence of thermal transport properties, the compound’s thermoelectric figure of merit reaches values up to ZT = 0.15 in the temperature range between room temperature and 523 K. Its structure is closely related to that of Ag10Te4Br3, another coinage metal polytelluride halide, which represents the first p\textendashn\textendashp-switchable semiconductor approachable by a simple temperature change. The title compound outperforms Ag10Te4Br3 in terms of thermoelectric properties by 1 order of magnitude and therefore acts as a link between the class of p\textendashn\textendashp compounds and thermoelectric materials.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Excited State Conformations of Bridged and Unbridged Pyrene Excimers},

author = {S Reiter and M K Roos and R De Vivie-Riedle},

url = {\<Go to ISI\>://WOS:000487014600024},

doi = {10.1002/cptc.201900096},

issn = {2367-0932},

year  = {2019},

date = {2019-05-06},

journal = {Chemphotochem},

volume = {3},

number = {9},

pages = {881-888},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Optimizing the Size of Platinum Nanoparticles for Enhanced Mass Activity in the Electrochemical Oxygen Reduction Reaction},

author = {B Garlyyev and K Kratzl and M R\"{u}ck and J Michali\v{c}ka and J Fichtner and J M Macak and T Kratky and S G\"{u}nther and M Cokoja and A S Bandarenka and A Gagliardi and R A Fischer},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201904492},

doi = {10.1002/anie.201904492},

issn = {1433-7851},

year  = {2019},

date = {2019-05-03},

journal = {Angewandte Chemie International Edition},

volume = {58},

number = {28},

pages = {9596-9600},

abstract = {Abstract High oxygen reduction (ORR) activity has been for many years considered as the key to many energy applications. Herein, by combining theory and experiment we prepare Pt nanoparticles with optimal size for the efficient ORR in proton-exchange-membrane fuel cells. Optimal nanoparticle sizes are predicted near 1, 2, and 3 nm by computational screening. To corroborate our computational results, we have addressed the challenge of approximately 1 nm sized Pt nanoparticle synthesis with a metal\textendashorganic framework (MOF) template approach. The electrocatalyst was characterized by HR-TEM, XPS, and its ORR activity was measured using a rotating disk electrode setup. The observed mass activities (0.87±0.14 A mgPt−1) are close to the computational prediction (0.99 A mgPt−1). We report the highest to date mass activity among pure Pt catalysts for the ORR within similar size range. The specific and mass activities are twice as high as the Tanaka commercial Pt/C catalysis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Oriented Thin Films of Electroactive Triphenylene Catecholate-Based Two-Dimensional Metal\textendashOrganic Frameworks},

author = {A M\"{a}hringer and A C Jakowetz and J M Rotter and B J Bohn and J K Stolarczyk and J Feldmann and T Bein and D D Medina},

url = {https://doi.org/10.1021/acsnano.9b01137},

doi = {10.1021/acsnano.9b01137},

issn = {1936-0851},

year  = {2019},

date = {2019-05-02},

journal = {ACS Nano},

volume = {13},

number = {6},

pages = {6711-6719},

abstract = {Two-dimensional triphenylene-based metal\textendashorganic frameworks (TP-MOFs) attract significant scientific interest due to their long-range order combined with significant electrical conductivity. The deposition of these structures as oriented films is expected to promote their incorporation into diverse optoelectronic devices. However, to date, a controlled deposition strategy applicable for the different members of this MOF family has not been reported yet. Herein, we present the synthesis of highly oriented thin films of TP-MOFs by vapor-assisted conversion (VAC). We targeted the M-CAT-1 series comprising hexahydroxytriphenylene organic ligands and metal-ions such as Ni2+, Co2+, and Cu2+. These planar organic building blocks are connected in-plane to the metal-ions through a square planar node forming extended sheets which undergo self-organization into defined stacks. Highly oriented thin Ni- and Co-CAT-1 films grown on gold substrates feature a high surface coverage with a uniform film topography and thickness ranging from 180 to 200 nm. The inclusion of acid modulators in the synthesis enabled the growth of films with a preferred orientation on quartz and on conductive substrates such as indium-doped tin oxide (ITO). The van der Pauw measurements performed across the M-CAT-1 films revealed high electrical conductivity values of up to 10\textendash3 S cm\textendash1 for both the Ni- and Co-CAT-1 films. Films grown on quartz allowed for a detailed photophysical characterization by means of UV\textendashvis, photoluminescence, and transient absorption spectroscopy. The latter revealed the existence of excited states on a nanosecond time scale, sufficiently long to demonstrate a photoinduced charge generation and extraction in Ni-CAT-1 films. This was achieved by fabricating a basic photovoltaic device with an ITO/Ni-CAT-1/Al architecture, thus establishing this MOF as a photoactive material. Our results point to the intriguing capabilities of these conductive M-CAT-1 materials and an additional scope of applications as photoabsorbers enabled through VAC thin-film synthesis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Monitoring the morphological evolution in mixed-dimensional lead bromide perovskite films with lamellar-stacked perovskite nanoplatelets},

author = {R Wang and Y Tong and K Wang and S Xia and E Kentzinger and O Soltwedel and P M\"{u}ller-Buschbaum and H Frielinghaus},

url = {http://dx.doi.org/10.1039/C9NH00156E},

doi = {10.1039/C9NH00156E},

issn = {2055-6756},

year  = {2019},

date = {2019-04-23},

journal = {Nanoscale Horizons},

volume = {4},

number = {5},

pages = {1139-1144},

abstract = {Mixed-dimensional lead bromide perovskite films combine the properties of both three-dimensional (3D) and two-dimensional (2D) perovskite crystals, and due to their good humidity tolerance, they emerge as promising candidates for long-term stable optoelectronic applications. In order to further tailor the film morphology aiming for a better device performance, it is important to unravel the structural formation mechanism in these perovskite thin films. In the present study, the formation of 3D lead bromide perovskite crystals and the self-assembly of lamellar-stacked 2D perovskite nanoplatelets are comprehensively studied. Samples are prepared through a two-step vapor assisted route with different vapor exposure times in order to monitor the detailed morphology at the specific reaction stage. With grazing incidence X-ray scattering techniques, the preferential orientation of the 3D crystals is found to decrease upon increasing the reaction time. Also, it is evidenced that well-ordered in-plane lamellar-stacked 2D nanoplatelets form aggregates in the bulk structure only. The obtained hierarchical morphology shows excellent structural stability in a humid atmosphere even at a relative humidity level of 80%. Our findings statistically offer a morphological understanding, which is important for the optimization of the sample preparation route and thus the resulting performance of moisture-tolerant perovskite based optoelectronic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Identifying and Reducing Interfacial Losses to Enhance Color-Pure Electroluminescence in Blue-Emitting Perovskite Nanoplatelet Light-Emitting Diodes},

author = {R L Z Hoye and M L Lai and M Anaya and Y Tong and K Galkowski and T Doherty and W W Li and T N Huq and S Mackowski and L Polavarapu and J Feldmann and J L Macmanus-Driscoll and R H Friend and A S Urban and S D Stranks},

url = {\<Go to ISI\>://WOS:000468015600025},

doi = {10.1021/acsenergylett.9b00571},

issn = {2380-8195},

year  = {2019},

date = {2019-04-17},

journal = {Acs Energy Letters},

volume = {4},

number = {5},

pages = {1181-1188},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Tuning the optical bandgap in layered hybrid perovskites through variation of alkyl chain length},

author = {J A Sichert and A Hemmerling and C Cardenas-Daw and A S Urban and J Feldmann},

url = {\<Go to ISI\>://WOS:000466615300017},

doi = {10.1063/1.5087296},

issn = {2166-532X},

year  = {2019},

date = {2019-04-16},

journal = {Apl Materials},

volume = {7},

number = {4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Structure and Charge Carrier Dynamics in Colloidal PbS Quantum Dot Solids},

author = {W Chen and J L Zhong and J Z Li and N Saxena and L P Kreuzer and H C Liu and L Song and B Su and D Yang and K Wang and J Schlipf and V Korstgens and T C He and K Wang and P Muller-Buschbaum},

url = {\<Go to ISI\>://WOS:000466991300006},

doi = {10.1021/acs.jpclett.9b00869},

issn = {1948-7185},

year  = {2019},

date = {2019-04-09},

urldate = {2019-04-09},

journal = {Journal of Physical Chemistry Letters},

volume = {10},

number = {9},

pages = {2058-2065},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The full dynamics of energy relaxation in large organic molecules: from photo-excitation to solvent heating},

author = {V Balevi\v{c}ius Jr and T Wei and D Di Tommaso and D Abramavicius and J Hauer and T Pol\'{i}vka and C D P Duffy},

url = {http://dx.doi.org/10.1039/C9SC00410F},

doi = {10.1039/C9SC00410F},

issn = {2041-6520},

year  = {2019},

date = {2019-04-02},

journal = {Chemical Science},

volume = {10},

number = {18},

pages = {4792-4804},

abstract = {In some molecular systems, such as nucleobases, polyenes or the active ingredients of sunscreens, substantial amounts of photo-excitation energy are dissipated on a sub-picosecond time scale, raising questions such as: where does this energy go or among which degrees of freedom it is being distributed at such early times? Here we use transient absorption spectroscopy to track excitation energy dispersing from the optically accessible vibronic subsystem into the remaining vibrational subsystem of the solute and solvent. Monitoring the flow of energy during vibrational redistribution enables quantification of local molecular heating. Subsequent heat dissipation away from the solute molecule is characterized by classical thermodynamics and molecular dynamics simulations. Hence, we present a holistic approach that tracks the internal temperature and vibronic distribution from the act of photo-excitation to the restoration of the global equilibrium. Within this framework internal vibrational redistribution and vibrational cooling are emergent phenomena. We demonstrate the validity of the framework by examining a highly controversial example, carotenoids. We show that correctly accounting for the local temperature unambiguously explains their energetically and temporally congested spectral dynamics without the ad hoc postulation of additional ‘dark’ states. An immediate further application of this approach would be to monitor the excitation and thermal dynamics of pigment\textendashprotein systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Unprecedented High Oxygen Evolution Activity of Electrocatalysts Derived from Surface-Mounted Metal\textendashOrganic Frameworks},

author = {W Li and S Watzele and H A El-Sayed and Y Liang and G Kieslich and A S Bandarenka and K Rodewald and B Rieger and R A Fischer},

url = {https://doi.org/10.1021/jacs.9b00549},

doi = {10.1021/jacs.9b00549},

issn = {0002-7863},

year  = {2019},

date = {2019-03-19},

journal = {Journal of the American Chemical Society},

volume = {141},

number = {14},

pages = {5926-5933},

abstract = {The oxygen evolution reaction (OER) is a key process for renewable energy storage. However, developing non-noble metal OER electrocatalysts with high activity, long durability and scalability remains a major challenge. Herein, high OER activity and stability in alkaline solution were discovered for mixed nickel/cobalt hydroxide electrocatalysts, which were derived in one-step procedure from oriented surface-mounted metal\textendashorganic framework (SURMOF) thin films that had been directly grown layer-by-layer on macro- and microelectrode substrates. The obtained mass activity of ∼2.5 mA·μg\textendash1 at the defined overpotential of 300 mV is 1 order of magnitude higher than that of the benchmarked IrO2 electrocatalyst and at least 3.5 times higher than the mass activity of any state-of-the-art NiFe-, FeCoW-, or NiCo-based electrocatalysts reported in the literature. The excellent morphology of the SURMOF-derived ultrathin electrocatalyst coating led to a high exposure of the most active Ni- and Co-based sites.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Flexible and Ultrasoft Inorganic 1D Semiconductor and Heterostructure Systems Based on SnIP},

author = {C Ott and F Reiter and M Baumgartner and M Pielmeier and A Vogel and P Walke and S Burger and M Ehrenreich and G Kieslich and D Daisenberger and J Armstrong and U K Thakur and P Kumar and S Chen and D Donadio and L S Walter and R T Weitz and K Shankar and T Nilges},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.201900233},

doi = {10.1002/adfm.201900233},

issn = {1616-301X},

year  = {2019},

date = {2019-03-13},

journal = {Advanced Functional Materials},

volume = {29},

number = {18},

pages = {1900233},

abstract = {Abstract Low dimensionality and high flexibility are key demands for flexible electronic semiconductor devices. SnIP, the first atomic-scale double helical semiconductor combines structural anisotropy and robustness with exceptional electronic properties. The benefit of the double helix, combined with a diverse structure on the nanoscale, ranging from strong covalent bonding to weak van der Waals interactions, and the large structure and property anisotropy offer substantial potential for applications in energy conversion and water splitting. It represents the next logical step in downscaling the inorganic semiconductors from classical 3D systems, via 2D semiconductors like MXenes or transition metal dichalcogenides, to the first downsizeable, polymer-like atomic-scale 1D semiconductor SnIP. SnIP shows intriguing mechanical properties featuring a bulk modulus three times lower than any IV, III-V, or II-VI semiconductor. In situ bending tests substantiate that pure SnIP fibers can be bent without an effect on their bonding properties. Organic and inorganic hybrids are prepared illustrating that SnIP is a candidate to fabricate flexible 1D composites for energy conversion and water splitting applications. SnIP@C3N4 hybrid forms an unusual soft material core\textendashshell topology with graphenic carbon nitride wrapping around SnIP. A 1D van der Waals heterostructure is formed capable of performing effective water splitting.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Spectral Screening of the Energy of Hot Holes over a Particle Plasmon Resonance},

author = {E Pensa and J Gargiulo and A Lauri and S Schl\"{u}cker and E Cort\'{e}s and S A Maier},

url = {https://doi.org/10.1021/acs.nanolett.8b04950},

doi = {10.1021/acs.nanolett.8b04950},

issn = {1530-6984},

year  = {2019},

date = {2019-03-13},

journal = {Nano Letters},

volume = {19},

number = {3},

pages = {1867-1874},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Ruthenium Oxide Nanosheets for Enhanced Oxygen Evolution Catalysis in Acidic Medium},

author = {S Laha and Y Lee and F Podjaski and D Weber and V Duppel and L M Schoop and F Pielnhofer and C Scheurer and K Muller and U Starke and K Reuter and B V Lotsch},

url = {\<Go to ISI\>://WOS:000465464500007},

doi = {10.1002/aenm.201803795},

issn = {1614-6832},

year  = {2019},

date = {2019-02-21},

journal = {Advanced Energy Materials},

volume = {9},

number = {15},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Quantifying Figures of Merit for Localized Surface Plasmon Resonance Applications: A Materials Survey},

author = {B Doiron and M Mota and M P Wells and R Bower and A Mihai and Y Li and L F Cohen and N M Alford and P K Petrov and R F Oulton and S A Maier},

url = {https://doi.org/10.1021/acsphotonics.8b01369},

doi = {10.1021/acsphotonics.8b01369},

year  = {2019},

date = {2019-02-20},

journal = {ACS Photonics},

volume = {6},

number = {2},

pages = {240-259},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Tuning the Fr\"{o}hlich exciton-phonon scattering in monolayer MoS2},

author = {B Miller and J Lindlau and M Bommert and A Neumann and H Yamaguchi and A W Holleitner and A H\"{o}gele and U Wurstbauer},

url = {https://doi.org/10.1038/s41467-019-08764-3},

doi = {10.1038/s41467-019-08764-3},

issn = {2041-1723},

year  = {2019},

date = {2019-02-18},

journal = {Nature Communications},

volume = {10},

number = {1},

pages = {807},

abstract = {Charge carriers in semiconducting transition metal dichalcogenides possess a valley degree of freedom that allows for optoelectronic applications based on the momentum of excitons. At elevated temperatures, scattering by phonons limits valley polarization, making a detailed knowledge about strength and nature of the interaction of excitons with phonons essential. In this work, we directly access exciton-phonon coupling in charge tunable single layer MoS2 devices by polarization resolved Raman spectroscopy. We observe a strong defect mediated coupling between the long-range oscillating electric field induced by the longitudinal optical phonon in the dipolar medium and the exciton. This so-called Fr\"{o}hlich exciton phonon interaction is suppressed by doping. The suppression correlates with a distinct increase of the degree of valley polarization up to 20% even at elevated temperatures of 220 K. Our result demonstrates a promising strategy to increase the degree of valley polarization towards room temperature valleytronic applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Exciton Diffusion Lengths and Dissociation Rates in CsPbBr3 Nanocrystal\textendashFullerene Composites: Layer-by-Layer versus Blend Structures},

author = {E-P Yao and B J Bohn and Y Tong and H Huang and L Polavarapu and J Feldmann},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.201801776},

doi = {10.1002/adom.201801776},

issn = {2195-1071},

year  = {2019},

date = {2019-02-18},

journal = {Advanced Optical Materials},

volume = {7},

number = {8},

pages = {1801776},

abstract = {Abstract Solution-processable perovskite nanocrystals (NCs) are gaining increasing interest in the field of photovoltaics because of their enhanced stability compared to their thin-film counterparts. However, the charge transfer dynamics in perovskite NC based light-harvesting systems are not well understood. By applying femtosecond differential transmission (DT) spectroscopy the photoinduced charge transfer from inorganic perovskite CsPbBr3 NCs to the fullerene derivative phenyl-C61-butyric acid methyl ester (PCBM) is investigated for two fundamentally different architectures, namely layer-by-layer heterostructures and blend structures. By varying the thickness of the NC layer on top of the PCBM in the layer-by-layer heterostructure, an exciton diffusion length of 290 ± 28 nm for CsPbBr3 NC is extracted. The diffusion process is followed by an ultrafast exciton dissociation (within 200 fs) at the CsPbBr3 NC/PCBM interface. In blend structures an overall faster charge transfer process is observed. Furthermore, photoconductivity measurements on a blend structure-based photodetector reveal an effective charge extraction from the active layer resulting in a high photosensitivity. DT measurements on this blend structure including adjacent electron- or hole-transport layers give insight into the extraction process and suggest a certain degree of phase segregation, which assists the charge collection.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Toward Plasmonic Tunnel Gaps for Nanoscale Photoemission Currents by On-Chip Laser Ablation},

author = {P Zimmermann and A H\"{o}tger and N Fernandez and A Nolinder and K M\"{u}ller and J J Finley and A W Holleitner},

url = {https://doi.org/10.1021/acs.nanolett.8b04612},

doi = {10.1021/acs.nanolett.8b04612},

issn = {1530-6984},

year  = {2019},

date = {2019-02-13},

journal = {Nano Letters},

volume = {19},

number = {2},

pages = {1172-1178},

abstract = {We demonstrate that prestructured metal nanogaps can be shaped on-chip to below 10 nm by femtosecond laser ablation. We explore the plasmonic properties and the nonlinear photocurrent characteristics of the formed tunnel junctions. The photocurrent can be tuned from multiphoton absorption toward the laser-induced strong-field tunneling regime in the nanogaps. We demonstrate that a unipolar ballistic electron current is achieved by designing the plasmonic junctions to be asymmetric, which allows ultrafast electronics on the nanometer scale.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{,

title = {Toward Plasmonic Tunnel Gaps for Nanoscale Photoemission Currents by On-Chip Laser Ablation},

author = {P Zimmermann and A H\"{o}tger and N Fernandez and A Nolinder and K M\"{u}ller and J J Finley and A W Holleitner},

url = {https://doi.org/10.1021/acs.nanolett.8b04612},

doi = {10.1021/acs.nanolett.8b04612},

issn = {1530-6984},

year  = {2019},

date = {2019-02-13},

journal = {Nano Letters},

volume = {19},

number = {2},

pages = {1172-1178},

abstract = {We demonstrate that prestructured metal nanogaps can be shaped on-chip to below 10 nm by femtosecond laser ablation. We explore the plasmonic properties and the nonlinear photocurrent characteristics of the formed tunnel junctions. The photocurrent can be tuned from multiphoton absorption toward the laser-induced strong-field tunneling regime in the nanogaps. We demonstrate that a unipolar ballistic electron current is achieved by designing the plasmonic junctions to be asymmetric, which allows ultrafast electronics on the nanometer scale.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}