Article
Chemistry, Physical
Gang-Hua Deng, Yuqin Qian, Xia Li, Tong Zhang, Wei Jiang, Avetik R. Harutyunyan, Gugang Chen, Hanning Chen, Yi Rao
Summary: This study utilized polarized transient absorption microscopy and ab initio simulations to investigate the role of vibronic coupling in singlet fission in pentacene. The findings revealed that a 35.0 cm(-1) phonon with vibrational coherence greatly facilitates singlet fission, resulting in notable directional anisotropicity in the fission rate. Additionally, the coherence-preserving phonon drives the formation of a decoupled triplet dimer from a correlated triplet pair.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
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
Chemistry, Physical
Jiayi Xu, Zilong Guo, Qinghua Zhou, Yaxin Wang, Zheng Xue, Yandong Han, Wensheng Yang, Xiaonan Ma
Summary: The exciton-phonon coupling in 2D hybrid perovskites are crucial for their optoelectronic properties, however, limited knowledge is available for the coupling between excitons and phonons of organic cations. This study systematically analyzed the temperature-dependent photoluminescence of I- and Br-based 2DHPs with different cations, revealing the critical role of organic cations and halide anions in exciton-phonon coupling and providing inspiration for designing high-performance 2DHP optoelectronic devices.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Xu Qiu, Guangjun Tian, Chengwei Lin, Yuyu Pan, Xiyun Ye, Bohan Wang, Dongge Ma, Dehua Hu, Yi Luo, Yuguang Ma
Summary: A design strategy to achieve narrowband emission of organic fluorescent emitters is proposed by enhancing low-frequency vibronic coupling while reducing high-frequency ones. The designed QAO derivatives exhibit better performance with narrowest band emissions in toluene and doped devices.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Optics
Rulin Miao, Yu Fu, Dazhi Lu, Fei Liang, Haohai Yu, Huaijin Zhang, Yicheng Wu
Summary: Coupling between electronic motions and lattice vibrations can increase the spectral bandwidth of fluorescence spectroscopy. However, the laser performances under electron-phonon coupling are mostly determined by experimental spectroscopy. The mechanism of multiphonon participation in laser emission is still unclear and requires further investigation.
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
M. S. Sutrisno, R. Hisam
Summary: The ionic and polaronic conduction in mixed ionic electronic glasses were analyzed using several theoretical models. The results showed that blocking effect, structural changes, and defect site concentration have significant influences on ionic and polaronic conductivity in the investigated glass samples.
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
Chemistry, Multidisciplinary
Qi Wang, Jiacheng Yang, Antoni Franco-Canellas, Christoph Buerker, Jens Niederhausen, Pierre Dombrowski, Felix Widdascheck, Tobias Breuer, Gregor Witte, Alexander Gerlach, Steffen Duhm, Frank Schreiber
Summary: A comprehensive study was conducted on the properties of donor-acceptor (D-A) bilayer structures, revealing that the characteristics of the bilayer structure on Au substrate are independent of the deposition sequence, while strong chemisorption occurs on Cu substrate, pinning down the PEN molecules.
NANOSCALE ADVANCES
(2021)
Article
Materials Science, Multidisciplinary
Lukas Eschmann, Jan Neuendorf, Michael Rohlfing
Summary: This study investigates the lifting phenomenon of physisorbates on surfaces under heating through simplified molecular dynamics simulation, showcasing the competition between different mechanisms and their impact on the occurring interface state. The findings demonstrate lifting of graphene and NTCDA on Ag(111) surface by 0.04 angstrom and 0.06 angstrom respectively between zero and room temperature. Additionally, the discussion on the temperature-dependent geometrical and vibrational properties provides insights into the understanding of interface state behavior.
Article
Materials Science, Multidisciplinary
Weng Hong Sio, Feliciano Giustino
Summary: This study investigates the Frohlich coupling in two-dimensional (2D) materials and derives a unified expression for the Frohlich matrix element in 2D systems. It avoids the use of Coulomb truncation and provides a simple expression applicable to model Hamiltonian approaches. The approach is validated through direct calculations and may have applications in various areas such as polaron calculations, quasiparticle renormalization, transport coefficients, and superconductivity in 2D and quasi-2D materials.
Article
Engineering, Electrical & Electronic
J. Nguepnang, C. Kenfack-Sadem, A. Kenfack-Jiotsa, C. Guimapi, A. J. Fotue, A. E. Merad
Summary: This paper theoretically investigates the effect of electron-phonon coupling on the dynamic and optical absorption of exciton-polaron in Transition Metal Dichalcogenides under a magnetic field. It is found that the absorption coefficient is influenced by the magnetic field, internal distance between TMDs monolayers and polar substrates, choice of polar substrates, and type of TMDs. Different characteristics are observed for weak, intermediate, and strong coupling regimes.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Chemistry, Physical
Robert B. Weakly, James D. Gaynor, Munira Khalil
Summary: This paper demonstrates experimental techniques for mapping coupled electronic and vibrational coordinates in complex systems through polarization-selective 2D VE and 2D EV spectroscopies. The study emphasizes the relationships between vibronic coupling parameters, Hamiltonian terms, and non-Condon effects, showing how they impact spectroscopic observables. The simulations of polarization-selective 2D EV and 2D VE spectra provide insights into measuring parameters of the vibronic Hamiltonian and non-Condon effects.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Condensed Matter
Mohd Alam, Labanya Ghosh, Srishti Dixit, Madhusmita Jena, Seema Kumari, Satya Vijay Kumar, Dheeraj Kumar, Abhineet Verma, A. K. Ghosh, Satyen Saha, R. J. Choudhary, Sandip Chatterjee
Summary: Transport, dielectric, magnetic and Raman studies were conducted on polycrystalline double perovskite EuTbCoMnO6. The results showed temperature-dependent resistivity following variable range and small polaron hopping mechanism, frequency-dependent step-like behavior in dielectric study, second-order phase transition around 113 K in magnetization study, and spin-phonon coupling in Raman study. The appearance of magnetocaloric effect and colossal dielectric constant indicates the potential real-life applications of these materials.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
Teng Zhang, Pamela H. W. Svensson, Iulia Emilia Brumboiu, Valeria Lanzilotto, Cesare Grazioli, Ambra Guarnaccio, Fredrik O. L. Johansson, Klara Beranova, Marcello Coreno, Monica de Simone, Luca Floreano, Albano Cossaro, Barbara Brena, Carla Puglia
Summary: In this article, the electronic structure modifications of triphenylamine (TPA) upon adsorption on Au(111) at a monolayer coverage are analyzed using various experimental and computational methods. The appearance of new unoccupied electronic states between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of free TPA indicates a considerable modification of its electronic structure. This finding has crucial implications for the design of molecular nanoelectronic devices based on similar donor systems.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Jinpeng Yang, Haruki Sato, Hibiki Orio, Xianjie Liu, Mats Fahlman, Nobuo Ueno, Hiroyuki Yoshida, Takashi Yamada, Satoshi Kera
Summary: In this study, the conduction band dispersion in methylammonium lead iodide (CH3NH3PbI3) was investigated using angle-resolved two-photon photoelectron spectroscopy (AR-2PPE) and angle-resolved low-energy inverse photoelectron spectroscopy (AR-LEIPS). The results showed significant energy dispersion along the Γ-M direction under different temperatures, consistent with band calculations under the cubic phase. The effective mass of electrons at the Γ point was estimated, and differences in conduction band energy were attributed to electronic-correlation-dependent processes.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Yasuo Nakayama, Koji Sudo, Noboru Ohashi, Satoshi Kera, Yasuyuki Watanabe
Summary: BTQBT is a promising material for vertical organic transistor devices due to its considerable energy dispersion in the valence band. In this study, the electronic structure at the interface of BTQBT on polycrystalline Au electrodes was elucidated using photoelectron spectroscopy (PES), revealing a widely dispersing valence band. The results derived a 75 meV intermolecular transfer integral and a hole effective mass of 4.3m(0) from the study.
ELECTRONIC STRUCTURE
(2021)
Article
Chemistry, Physical
Masato Iwasawa, Shinnosuke Kobayashi, Masahiro Sasaki, Yuri Hasegawa, Hiroyuki Ishii, Fumihiko Matsui, Satoshi Kera, Yoichi Yamada
Summary: In this study, we applied photoemission tomography (PT) to a unique one-dimensional row structure of a picene multilayer. We successfully deconvoluted the photoelectron momentum maps of three frontier orbitals of picene and determined the molecular orientation in the multilayer. This research marks an important step towards the wide-range utilization of PT technique.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Physics, Multidisciplinary
Fumihiko Matsui, Seiji Makita, Hiroyuki Matsuda, Eiken Nakamura, Yasuaki Okano, Takayuki Yano, Satoshi Kera, Shigemasa Suga
Summary: This study investigates four different resonant pathways in single-crystal graphite, revealing emission mechanisms such as participant Auger processes, spectator Auger processes, and a novel dispersion structure.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2021)
Article
Chemistry, Multidisciplinary
Jan Hagenlocher, Katharina Broch, Matthias Zwadlo, Daniel Lepple, Jonathan Rawle, Francesco Carla, Satoshi Kera, Frank Schreiber, Alexander Hinderhofer
Summary: Planar organic heterostructures are widely used in various devices, and the energy level alignment at different interfaces plays a crucial role in device performance. This study investigates the electronic and structural properties of perfluoropentacene-on-[6]phenacene heterostructure, finding that the material work function increases with thickness for both materials.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Yang Shen, Yan-Qing Li, Kai Zhang, Liu-Jiang Zhang, Feng-Ming Xie, Li Chen, Xiao-Yi Cai, Yu Lu, Hao Ren, Xingyu Gao, Haijiao Xie, Hongying Mao, Satoshi Kera, Jian-Xin Tang
Summary: Perovskite light-emitting diodes (PeLEDs) have potential in solution-processable display applications. However, the performance of blue PeLEDs is hindered by trap-mediated nonradiative recombination losses and halide phase segregation. Modulating mixed-halide perovskite materials through defect passivation can improve the performance of sky-blue PeLEDs, achieving high external quantum efficiency and stable emission.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Yuri Hasegawa, Fumihiko Matsui, Satoshi Kera
Summary: In this study, the photoelectron spectra of a highly-oriented-coronene monolayer on Au(111) were measured using a photoelectron momentum microscope (PMM). The research demonstrated the ability of the newly installed PMM apparatus to provide whole valence band mapping and site-selective resonant photoemission spectroscopy.
E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY
(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
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
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
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
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
Syed A. Abd-Rahman, Takuma Yamaguchi, Satoshi Kera, Hiroyuki Yoshida
Summary: The energy levels in organic semiconductors are determined by the molecular orbital energies, but recent studies have shown that the molecular orientation or mixing ratio in films can alter the energy levels due to intermolecular electrostatic interaction. This study investigates the coverage-dependent energy levels of zinc phthalocyanine and per-fluorinated zinc phthalocyanine using ultraviolet photoelectron spectroscopy and low-energy inverse photoelectron spectroscopy. The electrostatic energy was found to contribute significantly to the coverage-dependent energy shift.
Article
Nanoscience & Nanotechnology
Yongfeng Liu, Shi Tang, Junpeng Fan, Eduardo Gracia-Espino, Jinpeng Yang, Xianjie Liu, Satoshi Kera, Mats Fahlman, Christian Larsen, Thomas Wagberg, Ludvig Edman, Jia Wang
Summary: The synthesis of CsPbBr3 perovskite quantum dots (PeQDs) with high solubility in toluene has enabled their application as emitters in solution-processed light-emitting electrochemical cells (LECs). To achieve optimal performance, a thin solution-processed layer containing p-type poly(vinyl carbazole) and a tetrahexylammonium tetrafluoroborate ionic liquid is crucial to compensate for the as-synthesized n-type doping of the PeQDs.
ACS APPLIED NANO MATERIALS
(2021)
