Article
Chemistry, Multidisciplinary
Vyacheslav V. Sentyurin, Oleg A. Levitskiy, Alexey V. Bogdanov, Tatiana S. Yankova, Sergey G. Dorofeev, Konstantin A. Lyssenko, Victoria E. Gontcharenko, Tatiana V. Magdesieva
Summary: A new type of neutral mixed-valence system was synthesized using a one-pot procedure. The stability and energy barrier of intramolecular electron transfer in this system were influenced by a biphenyl bridge. The radicals in this system were determined to be Class II Robin-Day-mixed-valence systems through experimental and quantum-chemical study, and their structure was confirmed by X-ray data.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Yu-Ying Yang, Xiao-Quan Zhu, Jean-Pierre Launay, Cheng-Bin Hong, Shao-Dong Su, Yue-Hong Wen, Xin-Tao Wu, Tian-Lu Sheng
Summary: By synthesizing trimetallic isocyanidometal-bridged compounds with different oxidation states, the electron transfer process in oxidation reactions was investigated. The bridged states and mixed-valence states were simultaneously observed in N3+ compounds, while the electron transfer bridge excited state became more stable in N4+ compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Marcel Krug, Nina Frohlich, Dominik Fehn, Alexander Vogel, Frank Rominger, Karsten Meyer, Timothy Clark, Milan Kivala, Dirk M. Guldi
Summary: Three linear dimers containing two redox-active planarized triphenylamines were synthesized and their structures verified by X-ray crystallography. Investigation of their radical cations using various techniques revealed the significance of using redox centers with low internal reorganization energies. Distance-dependence attenuation factor of the super-exchange mechanisms remained similar when compared with non-planarized nitrogen-centered building blocks.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Matthew B. Gray, Jackson D. Majher, Noah P. Holzapfel, Patrick M. Woodward
Summary: The study investigates the structural and optical properties of halide substitutions of Br- and I- into (Cs4MM2Cl12)-M-II-Cl-III, showing that significant bromide incorporation is possible, while iodide incorporation is more limited. The larger halide ions can result in a red shift of the onset of optical absorption, providing insights into stabilizing the vacancy-ordered quadruple perovskite structure.
CHEMISTRY OF MATERIALS
(2021)
Article
Materials Science, Ceramics
Huanhuan Zhai, Zhuolin Liu, Jiaxin Tong, Yi Zhang, Binhua Zhou, Pengfei Tan, Rongjian Sa, Jun Pan
Summary: This study incorporates Pt clusters onto N vacancy engineered ultrathin g-C3N4 by a photo-deposition method to fabricate highly active photocatalysis. The Pt clusters on vUCN enable efficient electron transfer and band-gap optimization, resulting in superior photocatalytic performance.
CERAMICS INTERNATIONAL
(2023)
Editorial Material
Chemistry, Multidisciplinary
Paul J. J. Low
Summary: In a recent study by Cadranel and co-workers, time-resolved pump-probe spectroscopy was used to observe photo-induced metal-to-bridge charge transfer in the homovalent analogue of the Creutz-Taube ion. This resulted in two closely lying excited states with mixed-valence character, one with a shorter lifetime (136 ps) and weakly-coupled (Robin-Day Class II) character, and the other a longer-lived (2.8 ns) configurational isomer with more delocalized electronic structure. Electron transfer reactions from the longer-lived species showed similarities with the photoinduced reactions of the photosynthetic special pair, suggesting its potential as a reference system for excited state mixed-valency and photocatalytic reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Wenting Wu, Qinhua Zhang, Xiaodong Shao, Xuedong Zhao, Yinyong Ao, Liying Zhan, Zhongtao Li, Mingbo Wu
Summary: Metal centers confined in the porphyrin structure can process lower valence state via reversible photoinduced electron transfer, which is hardly influenced by the electronegative properties of surrounding porphyrin structures, and can be widely applied to various metal elements.
Article
Chemistry, Physical
Cameron C. L. Underwood, J. David Carey, S. Ravi P. Silva
Summary: The research shows a nonlinear band gap behavior with Sn content in mixed phase 2D Ruddlesden-Popper perovskites, providing critical insight for the design of future metal alloy 2D perovskite materials. The tunable energy band discontinuity positions may point to intraband transitions of interest to device engineers.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Energy & Fuels
Nada Alzahrani, Mohammed Benali Kanoun, Ahmed-Ali Kanoun, Souraya Goumri-Said
Summary: Mixed cation perovskite materials have shown great potential in solar cell devices, but the operating principles of these cells are not well understood. In this study, the photovoltaic performance of mixed cations-based perovskite solar cells was investigated using a device simulator program. The impact of thickness, doping concentration, density of defect, and band offsets on device performance were examined. The findings provide valuable insights for the design and construction of efficient mixed cations perovskite solar cell devices.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Shaosong Xin, Luning Ni, Peng Zhang, Haobin Tan, Mingyang Song, Tong Li, Yaowen Gao, Chun Hu
Summary: A highly active zinc-based single-atom catalyst with increased zinc loading has been developed, showing great potential for efficient removal of water pollutants. Experimental results demonstrate that the catalyst has a strong affinity to peroxydisulfate (PDS) and enables intense direct electron transfer from electron-rich pollutants.
Article
Materials Science, Ceramics
Chenfei Shi, Yuling Su, Gaoshang Gong, Huiyun Hu, Jin Zhou, Yongqiang Wang
Summary: This research investigates the vacancy defects, optical and magnetic properties of GdCr1-xTixO3 (0 <= x <= 0.05) polycrystalline samples. The results show that the crystal structure, magnetic properties, and optical band gap are affected by the substitution of Ti ions.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Rizwan Akram, Jan Sher Khan, Zahid Qamar, Saima Rafique, Mozaffar Hussain, Farrukh Bashir Kayani
Summary: Polyvinylpyrrolidone (PVP)-assisted bismuth telluride (Bi2Te3) fibers were synthesized by electrospinning technique, and compacted at a constant temperature. The compacted fibers showed improved thermoelectric performance and optical properties.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Chemistry, Physical
Da-Yong Lu, Xin Wei, Qian Cai
Summary: Ceramics with nominal compositions (Ba1-xNdx)(Ti1-xYbx)O-3 (BNTY) were prepared in air using a solid-state-reaction method. The co-solubility of Nd/Yb in BNTY determined by XRD was x = 0.05, and the sample with x = 0.05 (BNTY5) exhibited good dielectric properties with a pseudo-cubic structure and stable dielectric specifications at high temperatures. The presence of mixed valence states of Yb3+/Yb2+ and the reverse reducing effect were confirmed in BNTY5.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Mechanics
Shu-liang Cheng, Xiao-feng Li, Qun Yan, Bin Wang, Yong-tao Sun, Ya-jun Xin, Qian Ding, Hao Yan, Liang Wang
Summary: This paper presents two novel cruciate ligament structures that contribute significantly to lightweight design of metamaterials, band gap tuning, and ultra-wide and ultra-low frequency vibration and noise reduction, as well as providing a new design idea. The novelty of this paper lies in combining Bloch's theorem and finite element method to calculate the band gap, using the transfer function to verify the evaluation; using structural optimization and applying active strain to test the structural tunability; and illustrating the wave propagation and band gap opening mechanism from the vibration mode and energy perspectives. The results show that the structure has excellent vibration and sound insulation effect, with a wide range of band gap opening under active strain.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Chemistry, Physical
Michele Turelli, Gianluca Lattanzi, Ilaria Ciofini, Carlo Adamo
Summary: Limited control over the complex morphology exhibited by organic materials in the solid phase presents a major challenge in enhancing power conversion efficiency in organic photovoltaics. The molecular architecture of building blocks engineered with complex structures complicates self-organization mechanisms, hindering efficient control. Computational study of a small-molecule donor with simple architecture revealed significant changes in absorption spectrum in thin film upon thermal treatment, rationalized by molecular packing reorganization within the film. These findings provide valuable insights on improving morphology control in molecular solids.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Optics
Martin Aeschlimann, Tobias Brixner, Felix Fenner, Benjamin Frisch, Patrick Folge, Michael Hartelt, Matthias Hensen, Thomas H. Loeber, Walter Pfeiffer, Sebastian Pres, Bernd Stannowski
Summary: This study demonstrates the imaging of localized modes in golden Vogel spirals using photoemission electron microscopy (PEEM). The ability to visualize these modes offers a means to explore mode dynamics and perform nanospectroscopy.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Chemistry, Physical
Paul Weitz, Vincent Marc Le Corre, Xiaoyan Du, Karen Forberich, Carsten Deibel, Christoph J. Brabec, Thomas Heumueller
Summary: A method for accelerated stability testing of organic solar cells (OSCs) is presented using monochromatic light at high irradiation doses. The study reveals a degradation mechanism in PM6:Y6-based OSCs that causes an increased trap-state density inside the PM6:Y6 layer and highlights the dominant impact of illuminating wavelength on degradation patterns. The degradation rate of the devices scales linearly with light intensity, suggesting high intensity and spectrally selective degradation as a promising approach for accelerating stability testing of OSCs.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Julian Luettig, Peter A. Rose, Pavel Maly, Arthur Turkin, Michael Buehler, Christoph Lambert, Jacob J. Krich, Tobias Brixner
Summary: Time-resolved spectroscopy is widely used to study various phenomena in chemistry, biology, and physics. This study focuses on pump-probe experiments and coherent two-dimensional (2D) spectroscopy, which have been successful in visualizing energy transfer and electronic couplings. The researchers demonstrate that the appearance of a two-quantum (2Q) signal indicates the contamination of a one-quantum (1Q) signal by non-negligible fifth-order interactions. By performing partial integrations, the study shows that clean rQ signals can be obtained in 2D spectra, free from higher-order artifacts.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Daniel Fersch, Pavel Maly, Jessica Ruhe, Victor Lisinetskii, Matthias Hensen, Frank Wurthner, Tobias Brixner
Summary: We introduce fluorescence-detected pump-probe microscopy, which combines a wavelength-tunable ultrafast laser with a confocal scanning fluorescence microscope, allowing access to femtosecond timescales on a micrometer spatial scale. We demonstrate this approach on a model system of a terrylene bisimide dye embedded in a PMMA matrix, obtaining both the linear excitation spectrum and time-dependent pump-probe spectra simultaneously. By analyzing the statistical distribution of excitation spectra from single molecules, we investigate the effect of the molecular environment on excited-state energy.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Multidisciplinary Sciences
Pavel Maly, Julian Luettig, Peter A. Rose, Arthur Turkin, Christoph Lambert, Jacob J. Krich, Tobias Brixner
Summary: Quantum states depend on the coordinates of all their constituent particles, with essential multi-particle correlations. Time-resolved laser spectroscopy is widely used to probe the energies and dynamics of excited particles and quasiparticles. However, nonlinear signals from single- and multiple-particle excitations are all present simultaneously and cannot be disentangled without a priori knowledge of the system.
Article
Physics, Multidisciplinary
Sebastian Pres, Bernhard Huber, Matthias Hensen, Daniel Fersch, Enno Schatz, Daniel Friedrich, Victor Lisinetskii, Ruben Pompe, Bert Hecht, Walter Pfeiffer, Tobias Brixner
Summary: In this study, the local detection of nanoscale plasmon quantum wave packets was achieved using plasmon-assisted electron emission as a signal in coherent two-dimensional nanoscopy. The existence of a plasmon quantum wave packet was demonstrated, and an improved model for plasmon-assisted electron emission processes was provided.
Article
Physics, Multidisciplinary
Maria Saladina, Christopher Woepke, Clemens Goehler, Ivan Ramirez, Olga Gerdes, Chao Liu, Ning Li, Thomas Heumueller, Christoph J. Brabec, Karsten Walzer, Martin Pfeiffer, Carsten Deibel
Summary: The density of states (DOS) plays a crucial role in understanding physical processes in organic disordered semiconductors, but its experimental determination is challenging. In this study, we evaluated the DOS by investigating recombination through tail states and analyzing the temperature and open-circuit voltage (Voc) dependence of the ideality factor. Our Suns-Voc measurements revealed an increase in energetic disorder towards the deeper regions of the band gap, deviating from the expected Gaussian or exponential DOS. The observed linear dependence of disorder on energy suggests a power-law DOS in organic solar cells.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Organic
Emely Freytag, Lasse Kreimendahl, Marco Holzapfel, Jens Petersen, Heiko Lackinger, Matthias Stolte, Frank Wuerthner, Roland Mitric, Christoph Lambert
Summary: Five chiral squaraine dimers were synthesized by fusing chiral indolenine semisquaraines with three different benzobisthiazole bridges. The resulting dimers exhibited strong splitting of the lowest energy absorption bands due to exciton coupling. The electric circular dichroism spectra of the dimers showed intense Cotton effects whose sign depended on the used squaraine chromophores. TD-DFT calculations revealed that the electric-magnetic coupling was the dominant contribution to the rotational strength.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Julian Luttig, Stefan Mueller, Pavel Maly, Jacob J. Krich, Tobias Brixner
Summary: Transient absorption and coherent two-dimensional spectroscopy are commonly used methods for studying ultrafast dynamics in quantum systems. This article discusses the potential of higher-order pump-probe and multidimensional spectroscopy in providing insight into excited multiparticle states and their dynamics. The authors demonstrate how phase cycling can be used to isolate higher-order spectra in fluorescence-detected two-dimensional spectroscopy, and discuss the power of coherently detected fifth-order 2D spectroscopy in tracking exciton diffusion. They also show how higher-order signals can be extracted from ordinary pump-probe experiments to study multiexciton interactions and provide annihilation-free signals at high excitation densities.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Correction
Chemistry, Multidisciplinary
Avijit Maiti, Fangyuan Zhang, Ivo Krummenacher, Moulika Bhattacharyya, Sakshi Mehta, Michael Moos, Christoph Lambert, Bernd Engels, Abhishake Mondal, Holger Braunschweig, Prince Ravat, Anukul Jana
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Correction
Multidisciplinary Sciences
Pavel Maly, Julian Luttig, Peter A. A. Rose, Arthur Turkin, Christoph Lambert, Jacob J. J. Krich, Tobias Brixner
Article
Chemistry, Multidisciplinary
Lea Ress, Pavel Maly, Jann B. Landgraf, Dominik Lindorfer, Michael Hofer, Joshua Selby, Christoph Lambert, Thomas Renger, Tobias Brixner
Summary: This article presents the experimental and theoretical foundations for femtosecond time-resolved circular dichroism (TRCD) spectroscopy of excitonic systems. A new experimental setup, with a polarization grating as the key element, is introduced to generate circularly polarized pulses for TRCD experiments. By applying a specific chopping scheme, left and right circular polarizations can be switched, and transient absorption (TA) and TRCD spectra can be detected simultaneously. Experiments on a squaraine polymer are performed to investigate excitonic dynamics, and a general theory for TRCD experiments of excitonically coupled systems is developed and applied to describe the experimental data.
Article
Chemistry, Physical
Rik Hooijer, Andreas Weis, Waldemar Kaiser, Alexander Biewald, Patrick Doerflinger, Clement Maheu, Oleksandr Arsatiants, David Helminger, Vladimir Dyakonov, Achim Hartschuh, Edoardo Mosconi, Filippo De Angelis, Thomas Bein
Summary: Silver pnictohalides, as novel perovskite-inspired materials, have gained attention for their high stability, low toxicity, and promising efficiencies. However, research on the silver antimony iodides is lacking due to challenges in synthesis. In this study, the authors successfully prepared Ag-Sb-I thin films using thiourea as an additive and improved their morphology through alloying with copper. The resulting solar cells demonstrated an enhanced power conversion efficiency by reducing undesired side phases. The study also revealed the detrimental role of silver point defects and the beneficial effect of minor amounts of bismuth on the efficiency and stability of the Rudorffite materials.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Fridolin Saal, Asim Swain, Alexander Schmiedel, Marco Holzapfel, Christoph Lambert, Prince Ravat
Summary: We describe a helically chiral push-pull molecule named 9,10-dimethoxy-[7]helicene diimide, which exhibits fluorescence and circularly polarised luminescence over nearly the entire visible spectrum dependent on solvent polarity, along with high dissymmetry factors.
CHEMICAL COMMUNICATIONS
(2023)