14.
G Posnjak, X Yin, P Butler, O Bienek, M Dass, I D Sharp, T Liedl
Diamond photonic crystals assembled from DNA origami Journal Article
In: arXiv preprint arXiv:2310.10884, 0000.
Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized
@article{nokey,
title = {Diamond photonic crystals assembled from DNA origami},
author = {G Posnjak and X Yin and P Butler and O Bienek and M Dass and I D Sharp and T Liedl},
url = {https://arxiv.org/abs/2310.10884},
doi = {https://doi.org/10.48550/arXiv.2310.10884},
journal = {arXiv preprint arXiv:2310.10884},
abstract = {Colloidal self-assembly allows rational design of structures on the micron and submicron scale, potentially leading to physical material properties that are rare or non-existent in nature. One of the architectures that can generate complete 3D photonic band gaps is the diamond cubic lattice, which has remained difficult to realize at length scales comparable to the wavelength of visible light. Here, we demonstrate 3D photonic crystals self-assembled from DNA origami that act as precisely programmable patchy colloids. Our DNA-based nanoscale tetrapods crystallize into a rod-connected diamond cubic lattice with a periodicity of 170 nm that serves as a scaffold for atomic layer deposition of high refractive index materials such as TiO2, yielding a tunable photonic band gap in the near UV range.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}
Colloidal self-assembly allows rational design of structures on the micron and submicron scale, potentially leading to physical material properties that are rare or non-existent in nature. One of the architectures that can generate complete 3D photonic band gaps is the diamond cubic lattice, which has remained difficult to realize at length scales comparable to the wavelength of visible light. Here, we demonstrate 3D photonic crystals self-assembled from DNA origami that act as precisely programmable patchy colloids. Our DNA-based nanoscale tetrapods crystallize into a rod-connected diamond cubic lattice with a periodicity of 170 nm that serves as a scaffold for atomic layer deposition of high refractive index materials such as TiO2, yielding a tunable photonic band gap in the near UV range.
13.
L Richter, A M Szalai, C L Manzanares-Palenzuela, I Kamińska, P Tinnefeld
Exploring the Synergies of Single-Molecule Fluorescence and 2D Materials Coupled by DNA Journal Article
In: Advanced Materials, vol. 35, no. 41, pp. 2303152, 0000, ISSN: 0935-9648.
Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized
@article{nokey,
title = {Exploring the Synergies of Single-Molecule Fluorescence and 2D Materials Coupled by DNA},
author = {L Richter and A M Szalai and C L Manzanares-Palenzuela and I Kami\'{n}ska and P Tinnefeld},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202303152},
doi = {https://doi.org/10.1002/adma.202303152},
issn = {0935-9648},
journal = {Advanced Materials},
volume = {35},
number = {41},
pages = {2303152},
abstract = {Abstract The world of 2D materials is steadily growing, with numerous researchers attempting to discover, elucidate, and exploit their properties. Approaches relying on the detection of single fluorescent molecules offer a set of advantages, for instance, high sensitivity and specificity, that allow the drawing of conclusions with unprecedented precision. Herein, it is argued how the study of 2D materials benefits from fluorescence-based single-molecule modalities, and vice versa. A special focus is placed on DNA, serving as a versatile adaptor when anchoring single dye molecules to 2D materials. The existing literature on the fruitful combination of the two fields is reviewed, and an outlook on the additional synergies that can be created between them provided.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}
Abstract The world of 2D materials is steadily growing, with numerous researchers attempting to discover, elucidate, and exploit their properties. Approaches relying on the detection of single fluorescent molecules offer a set of advantages, for instance, high sensitivity and specificity, that allow the drawing of conclusions with unprecedented precision. Herein, it is argued how the study of 2D materials benefits from fluorescence-based single-molecule modalities, and vice versa. A special focus is placed on DNA, serving as a versatile adaptor when anchoring single dye molecules to 2D materials. The existing literature on the fruitful combination of the two fields is reviewed, and an outlook on the additional synergies that can be created between them provided.
12.
K Rickmeyer, M Huber, C R Hess
Influence of a neighbouring Cu centre on electro- and photocatalytic CO2 reduction by Fe-Mabiq Journal Article
In: Chemical Communications, 0000, ISSN: 1359-7345.
Abstract | Links | Tags: Foundry Organic
@article{nokey,
title = {Influence of a neighbouring Cu centre on electro- and photocatalytic CO2 reduction by Fe-Mabiq},
author = {K Rickmeyer and M Huber and C R Hess},
url = {http://dx.doi.org/10.1039/D3CC04777F},
doi = {10.1039/D3CC04777F},
issn = {1359-7345},
journal = {Chemical Communications},
abstract = {Electrocatalytic and photocatalytic CO2 reduction by a heterobimetallic Cu/Fe\textendashMabiq complex were examined and compared to the monometallic [Fe(Mabiq)]+. The neighbouring Cu\textendashXantphos unit leads to marked changes in the electrocatalytic mechanism and enhanced photocatalytic performance.},
keywords = {Foundry Organic},
pubstate = {published},
tppubtype = {article}
}
Electrocatalytic and photocatalytic CO2 reduction by a heterobimetallic Cu/Fe–Mabiq complex were examined and compared to the monometallic [Fe(Mabiq)]+. The neighbouring Cu–Xantphos unit leads to marked changes in the electrocatalytic mechanism and enhanced photocatalytic performance.
11.
M Righetto, S Caicedo-Dávila, M T Sirtl, V J Y Lim, J B Patel, D A Egger, T Bein, L M Herz
Alloying Effects on Charge-Carrier Transport in Silver–Bismuth Double Perovskites Journal Article
In: The Journal of Physical Chemistry Letters, vol. 14, no. 46, pp. 10340-10347, 0000.
Abstract | Links | Tags: Foundry Organic, Solid-Liquid
@article{nokey,
title = {Alloying Effects on Charge-Carrier Transport in Silver\textendashBismuth Double Perovskites},
author = {M Righetto and S Caicedo-D\'{a}vila and M T Sirtl and V J Y Lim and J B Patel and D A Egger and T Bein and L M Herz},
url = {https://doi.org/10.1021/acs.jpclett.3c02750},
doi = {10.1021/acs.jpclett.3c02750},
journal = {The Journal of Physical Chemistry Letters},
volume = {14},
number = {46},
pages = {10340-10347},
abstract = {Alloying is widely adopted for tuning the properties of emergent semiconductors for optoelectronic and photovoltaic applications. So far, alloying strategies have primarily focused on engineering bandgaps rather than optimizing charge-carrier transport. Here, we demonstrate that alloying may severely limit charge-carrier transport in the presence of localized charge carriers (e.g., small polarons). By combining reflection\textendashtransmission and optical pump\textendashterahertz probe spectroscopy with first-principles calculations, we investigate the interplay between alloying and charge-carrier localization in Cs2AgSbxBi1\textendashxBr6 double perovskite thin films. We show that the charge-carrier transport regime strongly determines the impact of alloying on the transport properties. While initially delocalized charge carriers probe electronic bands formed upon alloying, subsequently self-localized charge carriers probe the energetic landscape more locally, thus turning an alloy’s low-energy sites (e.g., Sb sites) into traps, which dramatically deteriorates transport properties. These findings highlight the inherent limitations of alloying strategies and provide design tools for newly emerging and highly efficient semiconductors.},
keywords = {Foundry Organic, Solid-Liquid},
pubstate = {published},
tppubtype = {article}
}
Alloying is widely adopted for tuning the properties of emergent semiconductors for optoelectronic and photovoltaic applications. So far, alloying strategies have primarily focused on engineering bandgaps rather than optimizing charge-carrier transport. Here, we demonstrate that alloying may severely limit charge-carrier transport in the presence of localized charge carriers (e.g., small polarons). By combining reflection–transmission and optical pump–terahertz probe spectroscopy with first-principles calculations, we investigate the interplay between alloying and charge-carrier localization in Cs2AgSbxBi1–xBr6 double perovskite thin films. We show that the charge-carrier transport regime strongly determines the impact of alloying on the transport properties. While initially delocalized charge carriers probe electronic bands formed upon alloying, subsequently self-localized charge carriers probe the energetic landscape more locally, thus turning an alloy’s low-energy sites (e.g., Sb sites) into traps, which dramatically deteriorates transport properties. These findings highlight the inherent limitations of alloying strategies and provide design tools for newly emerging and highly efficient semiconductors.
10.
M J Schilcher, D J Abramovitch, M Z Mayers, L Z Tan, D R Reichman, D A Egger
Correlated Anharmonicity and Dynamic Disorder Control Carrier Transport in Halide Perovskites Journal Article
In: arXiv preprint arXiv:2305.13682, 0000.
Abstract | Links | Tags: Foundry Organic
@article{nokey,
title = {Correlated Anharmonicity and Dynamic Disorder Control Carrier Transport in Halide Perovskites},
author = {M J Schilcher and D J Abramovitch and M Z Mayers and L Z Tan and D R Reichman and D A Egger},
url = {https://arxiv.org/abs/2305.13682},
doi = {https://doi.org/10.48550/arXiv.2305.13682},
journal = {arXiv preprint arXiv:2305.13682},
abstract = {Halide pervoskites are an important class of semiconducting materials which hold great promise for optoelectronic applications. In this work we investigate the relationship between vibrational anharmonicity and dynamic disorder in this class of solids. Via a multi-scale model parameterized from first-principles calculations, we demonstrate that the non-Gaussian lattice motion in halide perovskites is microscopically connected to the dynamic disorder of overlap fluctuations among electronic states. This connection allows us to rationalize the emergent differences in temperature-dependent mobilities of prototypical MAPbI3 and MAPbBr3 compounds across structural phase-transitions, in agreement with experimental findings. Our analysis suggests that the details of vibrational anharmonicity and dynamic disorder can complement known predictors of electronic conductivity and can provide structure-property guidelines for the tuning of carrier transport characteristics in anharmonic semiconductors.},
keywords = {Foundry Organic},
pubstate = {published},
tppubtype = {article}
}
Halide pervoskites are an important class of semiconducting materials which hold great promise for optoelectronic applications. In this work we investigate the relationship between vibrational anharmonicity and dynamic disorder in this class of solids. Via a multi-scale model parameterized from first-principles calculations, we demonstrate that the non-Gaussian lattice motion in halide perovskites is microscopically connected to the dynamic disorder of overlap fluctuations among electronic states. This connection allows us to rationalize the emergent differences in temperature-dependent mobilities of prototypical MAPbI3 and MAPbBr3 compounds across structural phase-transitions, in agreement with experimental findings. Our analysis suggests that the details of vibrational anharmonicity and dynamic disorder can complement known predictors of electronic conductivity and can provide structure-property guidelines for the tuning of carrier transport characteristics in anharmonic semiconductors.
9.
F Schuknecht, K Kołątaj, M Steinberger, T Liedl, T Lohmueller
Accessible hotspots for single-protein SERS in DNA-origami assembled gold nanorod dimers with tip-to-tip alignment Journal Article
In: Nature Communications, vol. 14, no. 1, pp. 7192, 0000, ISSN: 2041-1723.
Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized
@article{nokey,
title = {Accessible hotspots for single-protein SERS in DNA-origami assembled gold nanorod dimers with tip-to-tip alignment},
author = {F Schuknecht and K Ko\l\k{a}taj and M Steinberger and T Liedl and T Lohmueller},
url = {https://doi.org/10.1038/s41467-023-42943-7},
doi = {10.1038/s41467-023-42943-7},
issn = {2041-1723},
journal = {Nature Communications},
volume = {14},
number = {1},
pages = {7192},
abstract = {The label-free identification of individual proteins from liquid samples by surface-enhanced Raman scattering (SERS) spectroscopy is a highly desirable goal in biomedical diagnostics. However, the small Raman scattering cross-section of most (bio-)molecules requires a means to strongly amplify their Raman signal for successful measurement, especially for single molecules. This amplification can be achieved in a plasmonic hotspot that forms between two adjacent gold nanospheres. However, the small (≈1−2 nm) gaps typically required for single-molecule measurements are not accessible for most proteins. A useful strategy would thus involve dimer structures with gaps large enough to accommodate single proteins, whilst providing sufficient field enhancement for single-molecule SERS. Here, we report on using a DNA origami scaffold for tip-to-tip alignment of gold nanorods with an average gap size of 8 nm. The gaps are accessible to streptavidin and thrombin, which are captured at the plasmonic hotspot by specific anchoring sites on the origami template. The field enhancement achieved for the nanorod dimers is sufficient for single-protein SERS spectroscopy with sub-second integration times. This design for SERS probes composed of DNA origami with accessible hotspots promotes future use for single-molecule biodiagnostics in the near-infrared range.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}
The label-free identification of individual proteins from liquid samples by surface-enhanced Raman scattering (SERS) spectroscopy is a highly desirable goal in biomedical diagnostics. However, the small Raman scattering cross-section of most (bio-)molecules requires a means to strongly amplify their Raman signal for successful measurement, especially for single molecules. This amplification can be achieved in a plasmonic hotspot that forms between two adjacent gold nanospheres. However, the small (≈1−2 nm) gaps typically required for single-molecule measurements are not accessible for most proteins. A useful strategy would thus involve dimer structures with gaps large enough to accommodate single proteins, whilst providing sufficient field enhancement for single-molecule SERS. Here, we report on using a DNA origami scaffold for tip-to-tip alignment of gold nanorods with an average gap size of 8 nm. The gaps are accessible to streptavidin and thrombin, which are captured at the plasmonic hotspot by specific anchoring sites on the origami template. The field enhancement achieved for the nanorod dimers is sufficient for single-protein SERS spectroscopy with sub-second integration times. This design for SERS probes composed of DNA origami with accessible hotspots promotes future use for single-molecule biodiagnostics in the near-infrared range.
8.
D M Schwaiger, W Lohstroh, M Wolf, C J Garvey, P Müller-Buschbaum
In-situ study of degradation in PTB7:PCBM films prepared with the binary solvent additive DPE:DIO Journal Article
In: Journal of Polymer Science, vol. 61, no. 15, pp. 1660-1674, 0000, ISSN: 2642-4150.
Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized
@article{nokey,
title = {In-situ study of degradation in PTB7:PCBM films prepared with the binary solvent additive DPE:DIO},
author = {D M Schwaiger and W Lohstroh and M Wolf and C J Garvey and P M\"{u}ller-Buschbaum},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/pol.20230072},
doi = {https://doi.org/10.1002/pol.20230072},
issn = {2642-4150},
journal = {Journal of Polymer Science},
volume = {61},
number = {15},
pages = {1660-1674},
abstract = {Abstract Blend films of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7) in combination with 6,6-phenyl-C61-butyric-acid-methyl-ester (PCBM) are a model system for low bandgap organic photovoltaics. Typically, solvent additives are used to improve the power conversion efficiencies of the resulting devices but possibly also decrease the device stability. In this study, we use the binary solvent additive 1,8-diiodooctane:diphenylether (DIO:DPE) for PTB7:PCBM blend films and study how different film drying procedures influence the physical and chemical stability of the polymer blend. The strong influence of the drying procedure on the stability against photoinduced degradation of the PTB7:PCBM films, produced with solvent additives, is shown with data from UV\textendashvisible (UV\textendashvis), Fourier transform infrared (FTIR) and Raman spectroscopy. The addition of solvent additive molecules DIO:DPE to the PTB7:PCBM blend accelerates the degradation compared with the pristine blend. At higher annealing temperature a removal of the additives is bringing degradation back to the level of the pristine blend films, which is promising for photovoltaic applications.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}
Abstract Blend films of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7) in combination with 6,6-phenyl-C61-butyric-acid-methyl-ester (PCBM) are a model system for low bandgap organic photovoltaics. Typically, solvent additives are used to improve the power conversion efficiencies of the resulting devices but possibly also decrease the device stability. In this study, we use the binary solvent additive 1,8-diiodooctane:diphenylether (DIO:DPE) for PTB7:PCBM blend films and study how different film drying procedures influence the physical and chemical stability of the polymer blend. The strong influence of the drying procedure on the stability against photoinduced degradation of the PTB7:PCBM films, produced with solvent additives, is shown with data from UV–visible (UV–vis), Fourier transform infrared (FTIR) and Raman spectroscopy. The addition of solvent additive molecules DIO:DPE to the PTB7:PCBM blend accelerates the degradation compared with the pristine blend. At higher annealing temperature a removal of the additives is bringing degradation back to the level of the pristine blend films, which is promising for photovoltaic applications.
7.
A Semerci, A Buyruk, S Emin, R Hooijer, D Kovacheva, P Mayer, M A Reus, D Blätte, M Günther, N F Hartmann, S Lotfi, J P Hofmann, P Müller-Buschbaum, T Bein, T Ameri
In: Advanced Optical Materials, vol. 11, no. 16, pp. 2300267, 0000, ISSN: 2195-1071.
Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized
@article{nokey,
title = {A Novel Multi-Functional Thiophene-Based Organic Cation as Passivation, Crystalline Orientation, and Organic Spacer Agent for Low-Dimensional 3D/1D Perovskite Solar Cells},
author = {A Semerci and A Buyruk and S Emin and R Hooijer and D Kovacheva and P Mayer and M A Reus and D Bl\"{a}tte and M G\"{u}nther and N F Hartmann and S Lotfi and J P Hofmann and P M\"{u}ller-Buschbaum and T Bein and T Ameri},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adom.202300267},
doi = {https://doi.org/10.1002/adom.202300267},
issn = {2195-1071},
journal = {Advanced Optical Materials},
volume = {11},
number = {16},
pages = {2300267},
abstract = {Abstract Recently, the mixed-dimensional (3D/2D or 3D/1D) perovskite solar cells using small organic spacers have attracted interest due to their outstanding long-term stability. Here, a new type of thiophene-based organic cation 2-(thiophene-2yl-)pyridine-1-ium iodide (ThPyI), which is used to fabricate mixed-dimensional 3D/1D perovskite solar cells, is presented. The ThPyI-based 1D perovskitoid is applied as a passivator on top of a 3D methyl ammonium lead iodide (MAPI) to fabricate surface-passivated 3D/1D perovskite films or added alone into the 3D perovskite precursor to generate bulk-passivated 3D MAPI. The 1D perovskitoid acts as a passivating agent at the grain boundaries of surface-passivated 3D/1D, which improves the power conversion efficiency (PCE) of the solar cells. Grazing incidence wide-angle X-ray scattering (GIWAXS) studies confirm that ThPyI triggers the preferential orientation of the bulk MAPI slabs, which is essential to enhance charge transport. Champion bulk-passivated 3D and surface-passivated 3D/1D devices yield 14.10% and 19.60% PCE, respectively. The bulk-passivated 3D offers favorable stability, with 84% PCE retained after 2000 h without encapsulation. This study brings a new perspective to the design of organic spacers having a different binding motif and a passivation strategy to mitigate the impact of defects in hybrid 3D/1D perovskite solar cells.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}
Abstract Recently, the mixed-dimensional (3D/2D or 3D/1D) perovskite solar cells using small organic spacers have attracted interest due to their outstanding long-term stability. Here, a new type of thiophene-based organic cation 2-(thiophene-2yl-)pyridine-1-ium iodide (ThPyI), which is used to fabricate mixed-dimensional 3D/1D perovskite solar cells, is presented. The ThPyI-based 1D perovskitoid is applied as a passivator on top of a 3D methyl ammonium lead iodide (MAPI) to fabricate surface-passivated 3D/1D perovskite films or added alone into the 3D perovskite precursor to generate bulk-passivated 3D MAPI. The 1D perovskitoid acts as a passivating agent at the grain boundaries of surface-passivated 3D/1D, which improves the power conversion efficiency (PCE) of the solar cells. Grazing incidence wide-angle X-ray scattering (GIWAXS) studies confirm that ThPyI triggers the preferential orientation of the bulk MAPI slabs, which is essential to enhance charge transport. Champion bulk-passivated 3D and surface-passivated 3D/1D devices yield 14.10% and 19.60% PCE, respectively. The bulk-passivated 3D offers favorable stability, with 84% PCE retained after 2000 h without encapsulation. This study brings a new perspective to the design of organic spacers having a different binding motif and a passivation strategy to mitigate the impact of defects in hybrid 3D/1D perovskite solar cells.
6.
R Shafei, A Hamano, C Gourlaouen, D Maganas, K Takano, C Daniel, F Neese
In: The Journal of Chemical Physics, vol. 159, no. 8, 0000, ISSN: 0021-9606.
Abstract | Links | Tags: Foundry Organic, Solid-Liquid
@article{nokey,
title = {Theoretical spectroscopy for unraveling the intensity mechanism of the optical and photoluminescent spectra of chiral Re(I) transition metal complexes},
author = {R Shafei and A Hamano and C Gourlaouen and D Maganas and K Takano and C Daniel and F Neese},
url = {https://doi.org/10.1063/5.0153742},
doi = {10.1063/5.0153742},
issn = {0021-9606},
journal = {The Journal of Chemical Physics},
volume = {159},
number = {8},
abstract = {In this work, we present a computational study that is able to predict the optical absorption and photoluminescent properties of the chiral Re(I) family of complexes [fac-ReX(CO)3L], where X is either Cl or I and L is N-heterocyclic carbene extended with π-conjugated [5]-helicenic unit. The computational strategy is based on carefully calibrated time dependent density functional theory calculations and operates in conjunction with an excited state dynamics approach to treat in addition to absorption (ABS) and photoluminescence (PL), electronic circular dichroism (ECD), and circularly polarized luminescence (CPL) spectroscopies, respectively. The employed computational approach provides, an addition, access to the computation of phosphorescence rates in terms of radiative and non-radiative relaxation processes. The chosen molecules consist of representative examples of non-helicenic (NHC) and helicenic diastereomers. The agreement between theoretical and experimental spectra, including absorption (ABS, ECD) and emission (PL, CPL), is excellent, validating a quantitative interpretation of the spectral features on the basis of natural transition orbitals and TheoDore analyses. It is demonstrated that across the set of studied Re(I) diastereomers, the emission process in the case of NHC diastereomers is metal to ligand charge transfer in nature and is dominated by the easy-axis anisotropy of the emissive excited multiplet. On the contrary, in the cases of the helicenic diastereomers, the emission process is intra ligand charge transfer in nature and is dominated by the respective easy-plane anisotropy of the emissive excited multiplet. This affects remarkably the photoluminescent properties of the molecules in terms of PL and CPL spectral band shapes, spin-vibronic coupling, relaxation times, and the respective quantum yields. Spin-vibronic coupling effects are investigated at the level of the state-average complete active space self-consistent field in conjunction with quasi-degenerate second order perturbation theory. It is in fact demonstrated that a spin-vibronic coupling mechanism controls the observed photophysics of this class of Re(I) complexes.},
keywords = {Foundry Organic, Solid-Liquid},
pubstate = {published},
tppubtype = {article}
}
In this work, we present a computational study that is able to predict the optical absorption and photoluminescent properties of the chiral Re(I) family of complexes [fac-ReX(CO)3L], where X is either Cl or I and L is N-heterocyclic carbene extended with π-conjugated [5]-helicenic unit. The computational strategy is based on carefully calibrated time dependent density functional theory calculations and operates in conjunction with an excited state dynamics approach to treat in addition to absorption (ABS) and photoluminescence (PL), electronic circular dichroism (ECD), and circularly polarized luminescence (CPL) spectroscopies, respectively. The employed computational approach provides, an addition, access to the computation of phosphorescence rates in terms of radiative and non-radiative relaxation processes. The chosen molecules consist of representative examples of non-helicenic (NHC) and helicenic diastereomers. The agreement between theoretical and experimental spectra, including absorption (ABS, ECD) and emission (PL, CPL), is excellent, validating a quantitative interpretation of the spectral features on the basis of natural transition orbitals and TheoDore analyses. It is demonstrated that across the set of studied Re(I) diastereomers, the emission process in the case of NHC diastereomers is metal to ligand charge transfer in nature and is dominated by the easy-axis anisotropy of the emissive excited multiplet. On the contrary, in the cases of the helicenic diastereomers, the emission process is intra ligand charge transfer in nature and is dominated by the respective easy-plane anisotropy of the emissive excited multiplet. This affects remarkably the photoluminescent properties of the molecules in terms of PL and CPL spectral band shapes, spin-vibronic coupling, relaxation times, and the respective quantum yields. Spin-vibronic coupling effects are investigated at the level of the state-average complete active space self-consistent field in conjunction with quasi-degenerate second order perturbation theory. It is in fact demonstrated that a spin-vibronic coupling mechanism controls the observed photophysics of this class of Re(I) complexes.
5.
S Tu, T Tian, A Vagias, L F Huber, L Liu, S Liang, R A Fischer, S Bernstorff, P Müller-Buschbaum
In: Chemical Engineering Journal, vol. 477, pp. 147034, 0000, ISSN: 1385-8947.
Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized
@article{nokey,
title = {Modulation of electronic and ionic conduction in mixed polymer conductors via additive engineering: Towards targeted applications under varying humidity},
author = {S Tu and T Tian and A Vagias and L F Huber and L Liu and S Liang and R A Fischer and S Bernstorff and P M\"{u}ller-Buschbaum},
url = {https://www.sciencedirect.com/science/article/pii/S1385894723057650},
doi = {https://doi.org/10.1016/j.cej.2023.147034},
issn = {1385-8947},
journal = {Chemical Engineering Journal},
volume = {477},
pages = {147034},
abstract = {Polymer solids with mixed ion and electron transport hold great promise for next-generation organic electronics, and rational regulation of ionic/electronic contribution within these materials can enable a broadened spectrum of practical applications. However, a fundamental understanding of the conduction mechanisms and their correlations with morphological characteristics remains limited, especially under varying environmental humidity conditions. In the present work, simple additive engineering enables the effective regulation of electronic and ionic contribution in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) based conductors, giving rising to ion- and/or electron-dominant conductions. As a demonstration, PEDOT:PSS films with different electrical characteristics are successfully applied for thermal energy harvesting, healthcare monitoring and human motion detection upon humidity exposure. Combining operando alternating current (AC) impedance spectroscopy and grazing incidence small-angle X-ray scattering at low and high humidity levels, additive-dependent charge transport mechanisms are elucidated, and correlations between morphological alterations and conductivity evolutions are revealed. This work achieves highly tailorable PEDOT:PSS conduction utilizing Zonyl, dimethyl sulfoxide (DMSO) and carbon nanotubes (CNTs) as additives with distinct humidity responses and gains an in-depth comprehension of underlying mechanisms, which are expected to pave the way for next-generation organic electronics.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}
Polymer solids with mixed ion and electron transport hold great promise for next-generation organic electronics, and rational regulation of ionic/electronic contribution within these materials can enable a broadened spectrum of practical applications. However, a fundamental understanding of the conduction mechanisms and their correlations with morphological characteristics remains limited, especially under varying environmental humidity conditions. In the present work, simple additive engineering enables the effective regulation of electronic and ionic contribution in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) based conductors, giving rising to ion- and/or electron-dominant conductions. As a demonstration, PEDOT:PSS films with different electrical characteristics are successfully applied for thermal energy harvesting, healthcare monitoring and human motion detection upon humidity exposure. Combining operando alternating current (AC) impedance spectroscopy and grazing incidence small-angle X-ray scattering at low and high humidity levels, additive-dependent charge transport mechanisms are elucidated, and correlations between morphological alterations and conductivity evolutions are revealed. This work achieves highly tailorable PEDOT:PSS conduction utilizing Zonyl, dimethyl sulfoxide (DMSO) and carbon nanotubes (CNTs) as additives with distinct humidity responses and gains an in-depth comprehension of underlying mechanisms, which are expected to pave the way for next-generation organic electronics.
4.
C Wallach, Y Selic, F S Geitner, A Kumar, E Thyrhaug, J Hauer, A J Karttunen, T F Fässler
Probing Charge-Transfer Processes in a Covalently Linked [Ge9]-Cluster Imine Dyad Journal Article
In: Angewandte Chemie International Edition, vol. 62, no. 29, pp. e202304088, 0000, ISSN: 1433-7851.
Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized
@article{nokey,
title = {Probing Charge-Transfer Processes in a Covalently Linked [Ge9]-Cluster Imine Dyad},
author = {C Wallach and Y Selic and F S Geitner and A Kumar and E Thyrhaug and J Hauer and A J Karttunen and T F F\"{a}ssler},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202304088},
doi = {https://doi.org/10.1002/anie.202304088},
issn = {1433-7851},
journal = {Angewandte Chemie International Edition},
volume = {62},
number = {29},
pages = {e202304088},
abstract = {Abstract C60 donor dyads in which the carbon cage is covalently linked to an electron-donating unit have been discussed as one possibility for an electron-transfer system, and it has been shown that spherical [Ge9] cluster anions show a close relation to fullerenes with respect to their electronic structure. However, the optical properties of these clusters and of functionalized cluster derivatives are almost unknown. We now report on the synthesis of the intensely red [Ge9] cluster linked to an extended π-electron system. [Ge9Si(TMS)32CH3C=N-DAB(II)Dipp]− (1−) is formed upon the reaction of [Ge9Si(TMS)32]2− with bromo-diazaborole DAB(II)Dipp-Br in CH3CN (TMS=trimethylsilyl; DAB(II)=1,3,2-diazaborole with an unsaturated backbone; Dipp=2,6-di-iso-propylphenyl). Reversible protonation of the imine entity in 1− yields the deep green, zwitterionic cluster [Ge9Si(TMS)32CH3C=N(H)-DAB(II)Dipp] (1-H) and vice versa. Optical spectroscopy combined with time-dependent density functional theory suggests a charge-transfer excitation between the cluster and the antibonding π* orbital of the imine moiety as the cause of the intense coloration. An absorption maximum of 1-H in the red region of the electromagnetic spectrum and the corresponding lowest-energy excited state at λ=669 nm make the compound an interesting starting point for further investigations targeting the design of photo-active cluster compounds.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}
Abstract C60 donor dyads in which the carbon cage is covalently linked to an electron-donating unit have been discussed as one possibility for an electron-transfer system, and it has been shown that spherical [Ge9] cluster anions show a close relation to fullerenes with respect to their electronic structure. However, the optical properties of these clusters and of functionalized cluster derivatives are almost unknown. We now report on the synthesis of the intensely red [Ge9] cluster linked to an extended π-electron system. [Ge9Si(TMS)32CH3C=N-DAB(II)Dipp]− (1−) is formed upon the reaction of [Ge9Si(TMS)32]2− with bromo-diazaborole DAB(II)Dipp-Br in CH3CN (TMS=trimethylsilyl; DAB(II)=1,3,2-diazaborole with an unsaturated backbone; Dipp=2,6-di-iso-propylphenyl). Reversible protonation of the imine entity in 1− yields the deep green, zwitterionic cluster [Ge9Si(TMS)32CH3C=N(H)-DAB(II)Dipp] (1-H) and vice versa. Optical spectroscopy combined with time-dependent density functional theory suggests a charge-transfer excitation between the cluster and the antibonding π* orbital of the imine moiety as the cause of the intense coloration. An absorption maximum of 1-H in the red region of the electromagnetic spectrum and the corresponding lowest-energy excited state at λ=669 nm make the compound an interesting starting point for further investigations targeting the design of photo-active cluster compounds.
3.
F Wolf, M T Sirtl, S Klenk, M H H Wurzenberger, M Armer, P Dörflinger, P Ganswindt, R Guntermann, V Dyakonov, T Bein
Behind the scenes: insights into the structural properties of amide-based hole-transporting materials for lead-free perovskite solar cells Journal Article
In: CrystEngComm, vol. 25, no. 21, pp. 3142-3149, 0000.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Behind the scenes: insights into the structural properties of amide-based hole-transporting materials for lead-free perovskite solar cells},
author = {F Wolf and M T Sirtl and S Klenk and M H H Wurzenberger and M Armer and P D\"{o}rflinger and P Ganswindt and R Guntermann and V Dyakonov and T Bein},
url = {http://dx.doi.org/10.1039/D2CE01512A},
doi = {10.1039/D2CE01512A},
journal = {CrystEngComm},
volume = {25},
number = {21},
pages = {3142-3149},
abstract = {State-of-the-art perovskite solar cells often employ expensive organic hole transporting materials (HTM) such as spiro-OMeTAD, motivating the search for potential alternatives. Here we report single-crystal data of EDOT-amide-TPA as well as the first utilization of EDOT-amide-TPA as HTM for Cs2AgBiBr6 perovskite solar cells, outperforming spiro-OMeTAD. The dense packing of the EDOT-amide-TPA film improves the charge carrier extraction, increasing the JSC and PCE.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
State-of-the-art perovskite solar cells often employ expensive organic hole transporting materials (HTM) such as spiro-OMeTAD, motivating the search for potential alternatives. Here we report single-crystal data of EDOT-amide-TPA as well as the first utilization of EDOT-amide-TPA as HTM for Cs2AgBiBr6 perovskite solar cells, outperforming spiro-OMeTAD. The dense packing of the EDOT-amide-TPA film improves the charge carrier extraction, increasing the JSC and PCE.
2.
Y Xu, L Mewes, E Thyrhaug, V Sláma, F Šanda, H Langhals, J Hauer
Isolating Pure Donor and Acceptor Signals by Polarization-Controlled Transient Absorption Spectroscopy Journal Article
In: The Journal of Physical Chemistry Letters, vol. 14, no. 23, pp. 5390-5396, 0000.
Abstract | Links | Tags: Foundry Organic, Molecularly-Functionalized
@article{nokey,
title = {Isolating Pure Donor and Acceptor Signals by Polarization-Controlled Transient Absorption Spectroscopy},
author = {Y Xu and L Mewes and E Thyrhaug and V Sl\'{a}ma and F \v{S}anda and H Langhals and J Hauer},
url = {https://doi.org/10.1021/acs.jpclett.3c01451},
doi = {10.1021/acs.jpclett.3c01451},
journal = {The Journal of Physical Chemistry Letters},
volume = {14},
number = {23},
pages = {5390-5396},
abstract = {The optical spectra of molecules are often highly congested, inhibiting definite assignment of features and dynamics. In this work, we demonstrate and apply a polarization-based strategy for the decomposition of time-resolved optical spectra to analyze the electronic structure and energy transfer in a molecular donor\textendashacceptor (D\textendashA) dyad. We choose a dyad with orthogonal transition dipole moments for D and A and high fluorescence quantum yield to show that polarization-controlled ultrafast transient absorption spectra can isolate the pure D and A parts of the total signal. This provides a strategy to greatly reduce spectral congestion in complex systems and thus allows for detailed studies of electronic structure and electronic energy transfer.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}
The optical spectra of molecules are often highly congested, inhibiting definite assignment of features and dynamics. In this work, we demonstrate and apply a polarization-based strategy for the decomposition of time-resolved optical spectra to analyze the electronic structure and energy transfer in a molecular donor–acceptor (D–A) dyad. We choose a dyad with orthogonal transition dipole moments for D and A and high fluorescence quantum yield to show that polarization-controlled ultrafast transient absorption spectra can isolate the pure D and A parts of the total signal. This provides a strategy to greatly reduce spectral congestion in complex systems and thus allows for detailed studies of electronic structure and electronic energy transfer.
1.
F Ye, T Tian, J Su, R Jiang, J Li, C Jin, J Tong, S Bai, F Huang, P Müller-Buschbaum, Y-B Cheng, T Bu
Tailoring Low-Dimensional Perovskites Passivation for Efficient Two-Step-Processed FAPbI3 Solar Cells and Modules Journal Article
In: Advanced Energy Materials, vol. n/a, no. n/a, pp. 2302775, 0000, ISSN: 1614-6832.
Abstract | Links | Tags: Foundry Organic, Solid-Solid
@article{nokey,
title = {Tailoring Low-Dimensional Perovskites Passivation for Efficient Two-Step-Processed FAPbI3 Solar Cells and Modules},
author = {F Ye and T Tian and J Su and R Jiang and J Li and C Jin and J Tong and S Bai and F Huang and P M\"{u}ller-Buschbaum and Y-B Cheng and T Bu},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202302775},
doi = {https://doi.org/10.1002/aenm.202302775},
issn = {1614-6832},
journal = {Advanced Energy Materials},
volume = {n/a},
number = {n/a},
pages = {2302775},
abstract = {Abstract Converting PbI2 residues into low-dimensional perovskites through post-treatment with ammonium-based large cations can passivate 3D perovskites, thus has emerged as an effective strategy to improve the performance of perovskite solar cells (PSCs). Herein, a dramatically improved efficiency is demonstrated for PSCs based on a two-step-processed FAPbI3 perovskite via post-treatment with formamidinium (FA)-based benzamidine hydrochloride (PFACl), outperforming the commonly used methylamine (MA)-based benzylamine hydrochloride (PMACl). With an in-depth exploration of the crystal structures and morphology changes of the FAPbI3 perovskite upon the PFACl post-treatment, the preferential formation of 1D rather than 2D structures on the 3D perovskite film is identified. In contrast to the 2D counterpart, the more energetically favorable 1D structure enables a more effective elimination of PbI2 residues. As a consequence, the PFACl-induced 1D/3D perovskite film is endowed with smoother morphology, more uniform surface potential distribution, lower trap density, faster charge transfer, and better film stability than the PMACl-induced 2D/3D perovskite and control films, demonstrating champion efficiencies of 24.9% for a small-size PSC, 23.6% for a 1 cm2 large-size PSC, and 21.2% for a 5 × 5 cm2 mini-module, which is the highest among the perovskite solar mini-modules using the two-step deposition method.},
keywords = {Foundry Organic, Solid-Solid},
pubstate = {published},
tppubtype = {article}
}
Abstract Converting PbI2 residues into low-dimensional perovskites through post-treatment with ammonium-based large cations can passivate 3D perovskites, thus has emerged as an effective strategy to improve the performance of perovskite solar cells (PSCs). Herein, a dramatically improved efficiency is demonstrated for PSCs based on a two-step-processed FAPbI3 perovskite via post-treatment with formamidinium (FA)-based benzamidine hydrochloride (PFACl), outperforming the commonly used methylamine (MA)-based benzylamine hydrochloride (PMACl). With an in-depth exploration of the crystal structures and morphology changes of the FAPbI3 perovskite upon the PFACl post-treatment, the preferential formation of 1D rather than 2D structures on the 3D perovskite film is identified. In contrast to the 2D counterpart, the more energetically favorable 1D structure enables a more effective elimination of PbI2 residues. As a consequence, the PFACl-induced 1D/3D perovskite film is endowed with smoother morphology, more uniform surface potential distribution, lower trap density, faster charge transfer, and better film stability than the PMACl-induced 2D/3D perovskite and control films, demonstrating champion efficiencies of 24.9% for a small-size PSC, 23.6% for a 1 cm2 large-size PSC, and 21.2% for a 5 × 5 cm2 mini-module, which is the highest among the perovskite solar mini-modules using the two-step deposition method.