Article
Chemistry, Multidisciplinary
Kirill Kondratenko, David Guerin, Xavier Wallart, Stephane Lenfant, Dominique Vuillaume
Summary: This study investigates the electrical and thermal transport in thin films of a conducting polymer (PEDOT:OTf). The presence of highly conductive nano-domains is revealed by conductive atomic force microscopy (C-AFM). Thermal conductivity in the cross-plane direction is measured by null-point scanning thermal microscopy (NP-SThM). The results show a significant electronic contribution to the thermal transport.
Article
Materials Science, Multidisciplinary
Kenta Takada, Kohei Yoshimi, Satoshi Tsutsui, Koji Kimura, Kouichi Hayashi, Ikutaro Hamada, Susumu Yanagisawa, Naotaka Kasuya, Shun Watanabe, Jun Takeya, Yusuke Wakabayashi
Summary: The phonon dispersion of the organic semiconductor rubrene is experimentally measured by inelastic X-ray scattering experiments at room temperature. The results show that phonons are essential in organic crystals. However, there are few experimental reports on phonon dispersion in organic semiconductors. This study provides an important foundation for further investigation of organic semiconductors and understanding the lattice dynamics of highly anisotropic motifs.
Article
Chemistry, Multidisciplinary
Dipti Jasrasaria, Eran Rabani
Summary: This study developed an atomistic approach for describing exciton-phonon coupling in semiconductor nanocrystals and validated the method's reliability. Experimental results showed that exciton-phonon coupling leads to lattice distortion in nanocrystals, with surface modes playing a significant role in smaller nanocrystals and interior modes dominating in larger systems.
Article
Materials Science, Multidisciplinary
Ethan T. Ritz, Henrik S. Roising, Morten H. Christensen, Turan Birol, Brian M. Andersen, Rafael M. Fernandes
Summary: Recent experiments have shown that changes in the c-axis lattice parameter strongly affect the phase diagrams of the kagome superconductors AV3Sb5. It has been found that c-axis deformations primarily impact the overlap between the pz orbitals of the Sb apical bonds, thus significantly influencing low-energy electronic states with Sb character. Based on the orbital-selective character of c-axis strain, it is argued that these electronic states experience a non-negligible attractive electron-phonon pairing interaction mediated by fluctuations in the apical Sb bonds. Therefore, a multiband model is proposed to explain the superconductivity in AV3Sb5, which includes both the Sb pocket and the V-derived van Hove singularities.
Article
Multidisciplinary Sciences
Yigui Zhong, Shaozhi Li, Hongxiong Liu, Yuyang Dong, Kohei Aido, Yosuke Arai, Haoxiang Li, Weilu Zhang, Youguo Shi, Ziqiang Wang, Shik Shin, H. N. Lee, H. Miao, Takeshi Kondo, Kozo Okazaki
Summary: In the study, it was found that the new kagome metal CsV3Sb5 may have superconductivity that intertwines with time-reversal and spatial symmetry-breaking orders, suggesting an unconventional pairing mechanism. Through angle-resolved photoemission spectroscopy and Eliashberg function analysis, an EPC strength of lambda=0.45-0.6 for both Sb 5p and V 3d electronic bands was determined, supporting the conventional superconducting transition temperature in CsV3Sb5. Additionally, the EPC on the V 3d-band was enhanced to lambda~0.75 as the superconducting transition temperature elevated to 4.4 K in Cs(V0.93Nb0.07)(3)Sb-5. These results provide important insights into the pairing mechanism in the kagome superconductor CsV3Sb5.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Makena A. Dettmann, Lucas S. R. Cavalcante, Corina Magdaleno, Karina Masalkovait, Daniel Vong, Jordan T. Dull, Barry P. Rand, Luke L. Daemen, Nir Goldman, Roland Faller, Adam J. Moule
Summary: This study explores predicting atomic vibrational properties using six different simulation methods, with the Chebyshev-corrected tight-binding method showing the optimal combination of high accuracy and low expense. The research offers broad simulation guidelines for efficient, accurate prediction of inelastic neutron scattering spectrum.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Nanoscience & Nanotechnology
Nakul Jain, Ramakant Sharma, Suhas Mahesh, Dhanashree Moghe, Henry J. Snaith, Seunghyup Yoo, Dinesh Kabra
Summary: This study combines the radiative limit and MCT models to analyze the voltage losses in organic solar cells (OSCs), investigating nine different donor-acceptor systems and establishing relationships between V-OC, Urbach energy, and interfacial disorder.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Hagen Poddig, Dean Hobbis, Thomas Doert, George S. Nolas
Summary: The chemistry of new materials and the effects of chemical substitutions on physical properties continue to be of intense interest, with the synthesis and temperature-dependent transport properties of GdTe1.62Se0.18 revealing polaronic transport. Strong electron-phonon coupling is observed in this material, which also exhibits low thermal conductivity due to crystal structure and disorder in the Te-2(2-) anion.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Physical
Yi-Siang Wang, Chun- Wang, Chou-Hsun Yang, Chao-Ping Hsu
Summary: This work utilizes molecular dynamic simulations and machine-learning models to investigate dynamic disorder in the coupling of hole transfer. The results demonstrate that low-frequency modes dominate these dynamics, primarily resulting from intermolecular movements such as rotation and translation. Additionally, the coupling exhibits sub-Ohmic behavior in its spectral density character, with cut-off frequencies around 10(2) cm(-1).
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Michel Panhans, Sebastian Hutsch, Frank Ortmann
Summary: In this study, numerical and analytical quantum approaches are used to investigate the charge transfer dynamics in organic solids. The fading of transient localization and the formation of polarons are revealed in a wide range of vibrational frequencies and temperatures. Three distinct charge transport regimes, including transient localization, Soft Gating, and polaron transport, are identified, and the transitions between these regimes are found to be governed by the correlations between electronic motion and nuclei.
COMMUNICATIONS PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Shi-Ping Wang, Yu Wang, Fang-Yi Chen, Hai-Tao Wang, Fu-Kit Sheong, Fu-Quan Bai, Hong-Xing Zhang
Summary: The study evaluates the charge mobilities of a series of bis-1,3,4-oxadiazole derivatives using first-principles calculation, and discusses the impact of molecular overlap on charge mobility. It reveals that intermolecular distance and hole migration distance play crucial roles in achieving high electron mobility in pi stacking, while dihedral angle of anisotropy limits charge mobility in the herringbone arrangement. The correlation between crystal structure and charge mobility may assist experimental studies and improve the photoelectric conversion efficiency of organic semiconductor devices.
FRONTIERS IN CHEMISTRY
(2021)
Article
Physics, Applied
K. Park, J. Kim, S. Choi, S. Fan, C. Kim, D. G. Oh, N. Lee, S. -W Cheong, V. Kiryukhin, Y. J. Choi, D. Vanderbilt, J. H. Lee, J. L. Musfeldt
Summary: To explore the effects of spin-orbit coupling on spin-phonon interactions, we studied the infrared vibrational properties of chemically similar mixed metal oxides. Our findings showed significant shifts in the Co2+ shearing mode near 150 cm(-1) across the magnetic ordering temperature. These shifts were especially large in relative terms. The spin-phonon coupling constants were derived from interlayer exchange interactions and contained competing antiferromagnetic and ferromagnetic contributions.
APPLIED PHYSICS LETTERS
(2023)
Article
Crystallography
Andrey Y. Y. Sosorev, Dmitry I. I. Dominskiy, Nikita O. O. Dubinets
Summary: In this study, the charge-carrier mobilities in four single crystals of TADF luminophores with different molecular packing motifs were calculated. The results show that the molecular packing affects the transfer integrals between the molecules, leading to different charge mobilities.
Article
Energy & Fuels
Hui Zhang, Nam-Gyu Park
Summary: Organic-inorganic hybrid perovskites exhibit unique photophysical properties and are promising candidates for optoelectronic devices. Recent investigations have revealed that these properties are due to the formation of large polarons in the perovskite crystals, resulting from the coupling of photogenerated carriers and a polarized crystal lattice. This significantly affects the carrier transport dynamics and structural stability of perovskite solar cells.
JOURNAL OF PHYSICS-ENERGY
(2023)
Article
Physics, Multidisciplinary
Quynh L. D. Nguyen, Jacopo Simoni, Kevin M. Dorney, Xun Shi, Jennifer L. Ellis, Nathan J. Brooks, Daniel D. Hickstein, Amanda G. Grennell, Sadegh Yazdi, Eleanor E. B. Campbell, Liang Z. Tan, David Prendergast, Jerome Daligault, Henry C. Kapteyn, Margaret M. Murnane
Summary: By exciting nanoparticles, researchers have successfully created uniformly excited warm dense matter (WDM). Using photoelectron spectroscopy, they measured the instantaneous electron temperature and determined the strong coupling between the electrons and the ions. The findings are important for understanding the properties of WDM.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Di Wu, Shanshan Wan, Tianshu Zhai, Jiacheng Yang, Rongbin Wang, Steffen Duhm
Summary: UPS and XPS were used to investigate the impact of surface hydrophobicity on the work function of PEDOT:PSS thin films. Treatment of ITO by O2-plasma or UV-ozone did not affect the work function of PEDOT:PSS, while modification with a self-assembled monolayer of p-(trifluoromethyl)phenylphosphonic acid led to an increase in work function due to a PSS-rich surface.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Chemistry, Physical
Osamu Endo, Fumihiko Matsui, Satoshi Kera, Wang-Jae Chun, Masashi Nakamura, Kenta Amemiya, Hiroyuki Ozaki
Summary: The geometric and electronic structures of perylene monolayers on gold single-crystal surfaces and the impact of Br doping were investigated. The study found that perylene molecules adsorbed on the Au(110)(1 x 2) surface form a monolayer with a specific orientation, while on the Au(111) surface, parallel molecular planes are observed. Additionally, the study found that doped Br can penetrate the perylene monolayer and cause a significant change in molecular orientation. Cationic perylene exhibits resonance with the singly unoccupied molecular orbital (SUMO) in the C K NEXAFS spectra.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Taku Oono, Takuya Okada, Tsubasa Sasaki, Kaito Inagaki, Takuma Ushiku, Takahisa Shimizu, Takuji Hatakeyama, Hirohiko Fukagawa
Summary: Understanding and improving hole-injection mechanism is crucial for the development of organic optoelectronic devices. By controlling the charged state of an electron-acceptor molecule, efficient and stable hole injection can be achieved, enabling the realization of a pure blue organic light-emitting diode with low turn-on voltage, high power efficiency, and high quantum efficiency.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Kewei Sun, Orlando J. Silveira, Yujing Ma, Yuri Hasegawa, Michio Matsumoto, Satoshi Kera, Ondrej Krejci, Adam S. Foster, Shigeki Kawai
Summary: Substituting carbon with silicon in organic molecules and materials is a challenging task, but in this study, the researchers successfully synthesized one- and two-dimensional covalent organic frameworks with atomically precise Si substitution. The structures were characterized using high-resolution scanning tunnelling microscopy and photoelectron spectroscopy, and it was found that each Si atom in a hexagonal C4Si2 ring was covalently linked to one terminal Br atom.
Article
Materials Science, Multidisciplinary
Li Zhang, Melissa Berteau-Rainville, Tianshu Zhai, Yuhao Wang, Qi Wang, Ingo Salzmann, Steffen Duhm
Summary: The energy-level alignment (ELA) at interfaces plays a crucial role in organic optoelectronic applications by determining the device performance. The ELA at organic-inorganic interfaces in organic thin films is influenced by gap states and/or tailing states of the frontier molecular orbitals. The susceptibility of conjugated organic materials to chemical and structural defects is highlighted as a key factor in the ELA at interfaces.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Chinatsu Satoh, Takuya Okada, Taku Oono, Tsubasa Sasaki, Takahisa Shimizu, Hirohiko Fukagawa
Summary: A simple equation describing the minimum voltage required for OLED operation is reported, which takes into account the bandgap of the emitter and other relevant energies. It is found that the minimum voltage required for OLED operation is at least 0.7 V lower than the emitter's bandgap divided by the elementary charge, thanks to the relatively high exciton binding energy of organic materials. Based on these findings, D/A molecules are designed for ultra-low-voltage operation of OLEDs, and green and blue OLEDs emitting light at approximately 1.5 V are achieved through triplet-triplet annihilation photon upconversion.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Osamu Endo, Fumihiko Matsui, Satoshi Kera, Wang-Jae Chun, Masashi Nakamura, Kenta Amemiya, Hiroyuki Ozaki
Summary: Photoemission spectroscopy was used to study the perylene layers on the Au(110) surface using a momentum microscope. The two-dimensional momentum maps showed a binary star pattern for the perylene mono layer, indicating the tilted molecular orientation. This pattern was absent for the perylene multilayer and the Br-doped monolayer due to random molecular orientation. Br doping facilitated hole injection in perylene, and electrons from the singly occupied molecular orbital were observed at binding energies of 1.0-1.5 eV.
E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY
(2023)
Article
Chemistry, Physical
S. Kera, F. Matsui, K. Tanaka, Y. Taira, T. Araki, T. Ohigashi, H. Iwayama, M. Fujimoto, H. Matsuda, E. Salehi, M. Katoh
Summary: The synchrotron radiation facility is a large-scale public infrastructure that provides advanced light sources and is used for various academic research and application development. For 40 years, UVSOR Synchrotron Facility has been leading the field as a facility that has developed and utilized cutting-edge light source technology in the low-photon-energy regime. The next UVSOR aims to establish a center for quantum photon science research through the development of unexplored characterization technologies by advanced use of light sources and a measurement and analysis support environment.
ELECTRONIC STRUCTURE
(2023)
Article
Chemistry, Physical
Yuan Zhang, Qi Wang, Fengyang Hu, Yuhao Wang, Di Wu, Rongbin Wang, Steffen Duhm
Summary: In this study, PEDOT:PSS thin films with seven different additive combinations were prepared and their properties were analyzed. It was found that the work function of the thin films became saturated at a thickness of around 50 nm, and thinner films exhibited lower work function due to incomplete coverage on the ITO substrate. The PSS-to-PSSH ratio showed better correlation with the work function than the commonly used PSS-to-PEDOT ratio. Solvent additives dramatically increased the conductivity of the PEDOT:PSS films, especially when DMSO was involved. Additionally, the surfactant Triton helped to suppress the work function fluctuation and weaken the surface dipole, resulting in a lower and thickness-independent work function.
ACS PHYSICAL CHEMISTRY AU
(2023)
Article
Chemistry, Physical
Yuhao Wang, Yuan Zhang, Li Zhang, Qi Wang, Steffen Duhm
Summary: Graphene nanoribbons (GNRs) are promising materials for nanoscale electronic devices due to their exceptional stability and unique electronic and optical properties. In this study, we investigate the formation process of 7-GNRs on Au(111), Ag(111), and Cu(111) substrates using 10,10'-Dibromo-9,9'-bianthracene (DBBA) as the precursor. X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) are utilized to track the reaction pathways. Our results demonstrate that the substrate reactivity plays a crucial role in the growth behavior of GNRs.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Instruments & Instrumentation
Fumihiko Matsui, Kenta Hagiwara, Eiken Nakamura, Takayuki Yano, Hiroyuki Matsuda, Yasuaki Okano, Satoshi Kera, Eri Hashimoto, Shinji Koh, Keiji Ueno, Takahiro Kobayashi, Emi Iwamoto, Kazuyuki Sakamoto, Shin-ichiro Tanaka, Shigemasa Suga
Summary: The photoelectron momentum microscope (PMM) is a new method that can effectively reduce radiation-induced damage by projecting a single photoelectron energy contour onto a two-dimensional detector. It has been used for measuring the three-dimensional valence band structure and energy variations in different experimental conditions. This technique has been successfully applied to observe the band structure of thin films and investigate the changes in photoelectron energy and band structure in different materials. Furthermore, comparisons and discussions of different PMMs with various electron analyzers have been conducted.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Engineering, Electrical & Electronic
Fengyang Hu, Melissa Berteau-Rainville, Hannes Hase, Yuan Zhang, Qi Wang, Ingo Salzmann, Steffen Duhm
Summary: The position of the Fermi level in doped organic semiconductors is determined by both dopant loading and energy-level alignment with the substrate. Experimental and numerical modeling studies have shown the effects of energy-level alignment on Fermi level position and electron transfer between materials.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Zong-Guang Ma, Yang Shen, Kai Zhang, Long-Xue Cao, Hao Ren, Wei-Shuo Chen, Huai-Xin Wei, Yan-Qing Li, Satoshi Kera, Jian-Xin Tang
Summary: In this study, bifunctional additive engineering using nicotinohydrazide (NHD) with two effective groups (-N2H3 and -C=O) was employed to improve the performance of tin-based PeLEDs. The oxidation of Sn2+ was suppressed and the perovskite morphology was optimized, leading to the achievement of a pure-red PeLED emitting at 628 nm with elevated electroluminescence efficiency and stability. The results provide an effective strategy for the development of lead-free PeLEDs.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Qi Wang, Jiacheng Yang, Alexander Gerlach, Frank Schreiber, Steffen Duhm
Summary: Organic-metal and organic-organic interfaces play a crucial role in the functionality of organic optoelectronic applications. Accurate estimation of energy-level alignment is challenging due to various interfacial effects. XPS and UPS measurements provide guidelines for interpreting the energy-level alignment of these interfaces.
JOURNAL OF PHYSICS-MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Min Xu, Botong Chen, Qi Wang, Yuan Zhang, Yuhao Wang, Steffen Duhm, Lijia Liu
Summary: In this study, it is confirmed through experiments and analysis that CH3 typically binds to Pb in MAPbBr(3) films, forming CH3-Pb species.
MRS COMMUNICATIONS
(2022)
