A5064612411- Molecular Junctions and Nanostructures
- Organic Electronics and Photovoltaics
- Electron and X-Ray Spectroscopy Techniques
- Surface Chemistry and Catalysis
- Advanced Chemical Physics Studies
- Surface and Thin Film Phenomena
- Graphene research and applications
- Quantum Dots Synthesis And Properties
- Conducting polymers and applications
- Perovskite Materials and Applications
- Organic Light-Emitting Diodes Research
- Semiconductor materials and devices
- Machine Learning in Materials Science
- Fullerene Chemistry and Applications
- Organic and Molecular Conductors Research
- Porphyrin and Phthalocyanine Chemistry
- Advanced Electron Microscopy Techniques and Applications
- Transition Metal Oxide Nanomaterials
- Chalcogenide Semiconductor Thin Films
- Electrocatalysts for Energy Conversion
- Force Microscopy Techniques and Applications
- Quantum and electron transport phenomena
- Photochemistry and Electron Transfer Studies
- X-ray Spectroscopy and Fluorescence Analysis
- Spectroscopy and Quantum Chemical Studies
Institute for Molecular Science
2015-2024
The Graduate University for Advanced Studies, SOKENDAI
2016-2024
National Institutes of Natural Sciences
2016-2023
Nippon Soken (Japan)
2019-2021
Chiba University
2011-2020
Soochow University
2014
Shandong University
2014
Kyoto Bunkyo University
2013
Kyoto University
2013
Kyoto University Institute for Chemical Research
2013
The electronic structure of rubrene single crystals was studied by angle-resolved ultraviolet photoelectron spectroscopy. A clear energy dispersion the highest occupied molecular orbital-derived band observed, and width found to be 0.4 eV along well-stacked direction. effective mass holes estimated $0.65(\ifmmode\pm\else\textpm\fi{}0.1){m}_{0}$. present results suggest that carrier conduction mechanism in can described within framework transport.
The electronic structure of pentacene/graphite, pentacene/Cu-phthalocyanine (CuPc)/graphite, and $\text{pentacene}∕\mathrm{Si}{\mathrm{O}}_{2}∕\mathrm{Si}(100)$ was studied by ultraviolet photoelectron spectroscopy as a function the thickness pentacene film. We observed that binding energy position highest occupied molecular orbital (HOMO) becomes significantly lower on CuPc $\mathrm{Si}{\mathrm{O}}_{2}$ surfaces than graphite. Furthermore, splitting UPS band only for HOMO thicker...
We detected a very low density of electronic states in the band gap nondoped pentacene thin film by using ultraviolet photoelectron spectroscopy with ultrahigh sensitivity and ultralow background. The states, which may originate from highest occupied molecular orbital (HOMO) state imperfect packing regions, are distributed exponentially up to Fermi level control relative HOMO band.
Solution-processed perovskite solar cells are attracting increasing interest due to their potential in next-generation hybrid photovoltaic devices. Despite the morphological control over films, quantitative information on electronic structures and interface energetics is of paramount importance optimal performance. Here, direct inverse photoemission spectroscopies used determine chemical compositions various methylammonium lead halide films (MAPbX3, X = Cl, Br, I), revealing strong influence...
We studied gas-exposure effects on pentacene (Pn) films SiO2 and Au(111) substrates by ultrahigh sensitivity photoelectron spectroscopy, which can detect the density of states ∼10(16) eV-1 cm-3 comparable to electrical measurements. The results show striking for Pn/SiO2: exposure inert gas (N2 Ar) produces a sharp rise in gap from ∼10(18) pushes Fermi level closer valence band (0.15-0.17 eV), as does O2 (0.20 while no such effect is observed Pn/Au(111). demonstrate that these originate small...
Abstract Perovskite light‐emitting didoes (PeLEDs) have shown considerable potential in solution‐processable display applications. However, the performance of blue PeLEDs terms efficiency and stability hinders their practicality on account severe trap‐mediated nonradiative recombination losses halide phase segregation. To ameliorate these issues, mixed‐halide sky‐blue perovskite materials are strategically modulated through crystal defect passivation with a trifurcate isocyanate oligomer,...
Substituting carbon with silicon in organic molecules and materials has long been an attractive way to modify their electronic structure properties. Silicon-doped graphene-based are known exhibit exotic properties, yet conjugated atomically precise Si substitution have remained difficult prepare. Here we present the on-surface synthesis of one- two-dimensional covalent frameworks whose backbones contain 1,4-disilabenzene (C4Si2) linkers. Silicon atoms were first deposited on a Au(111)...
The effect of an interface dipole layer on the energy level alignment at organic-conductor interfaces is studied a copper phthalocyanine (CuPc) monolayer/electric layer/graphite system via ultraviolet photoemission spectroscopy (UPS) and metastable atom electron spectroscopy. An oriented monolayer OTi-phthalocyanine molecule, which has electric moment, grown graphite to yield well-defined with vacuum side negatively charged. CuPc sequentially deposited kept...
Changes in the work function (WF) and binding energy of highest occupied molecular orbital (HOMO) level a titanyl phthalocyanine-(OTiPc) graphite system were studied as OTiPc coverage by ultraviolet photoelectron spectroscopy. We observed that WF increases with oriented until formation monolayer, while position HOMO stays almost unchanged respect to Fermi level. By analyzing dependence using Topping model, we estimated electric dipole moment polarizability monolayer.
The charge-injection barriers at interfaces of a pentacene monolayer are investigated. It is found that the barrier depends on substrate work function. Substrate functions smaller than ionization potential film have vacuum-level alignment, whereas for exceeding film, HOMO pinned to near Fermi level (see figure).
Abstract The electronic structure of the interfaces formed after deposition MoO 3 hole‐injection layers on top a polymer light‐emitting material, poly(dioctylfluorene‐ alt ‐benzothiadiazole) (F8BT), is studied by ultraviolet photoelectron spectroscopy (UPS), X‐ray and metastable atom electron spectroscopy. Significant band bending induced in F8BT film “acceptors” that spontaneously diffuse into “host” probably driven kinetic energy deposited hot . Further leads to saturation accompanied...
Changes in the work function (WF) of phthalocyanine-graphite systems were investigated as functions phthalocyanine coverage and value molecular dipole moment by using ultraviolet photoelectron spectroscopy. The dipoles film found to be perpendicular graphite surface, dependence WF each dipole-phthalocyanine--graphite system clearly exhibited a sudden increase before monolayer formation depending on moment. results show that dipole-dipole repulsive interaction impacts growth structure with...
Abstract Making electronic devices using a single molecule has been the ultimate goal of molecular electronics. For binary data storage in particular, challenge ability to switch between bistable states simple and repeatable manner. The reversible switching molecules chloroaluminum phthalocyanine (ClAlPc) dipolar within close‐packed monolayer is demonstrated. By pulsing an scanning tunneling microscopy tip, read–write operations single‐molecular bits at ∼40 Tb/cm 2 (∼250 Tb/in ) are
Phthalocyanines are an important class of organic semiconductors and, thus, their interfaces with metals both fundamental and practical relevance. In the present contribution we provide a combined theoretical experimental study, in which show that state-of-the-art quantum-mechanical simulations nowadays capable treating most properties such quantitatively reliable manner. This is shown for Cu-phthalocyanine (CuPc) Zn-phthalocyanine (ZnPc) on Au(111) Ag(111) surfaces. Using recently developed...
Methodologies and experimental achievements for exploration into electronic band structures of organic semiconductor hybrid perovskite single crystals are reviewed.
The electronic structure of a well-oriented perylene-3,4,9,10-tetracarboxylic acid-dianhydride multilayer prepared on ${\mathrm{MoS}}_{2}$ single crystal surface were studied by angle-resolved ultraviolet photoemission spectroscopy using synchrotron radiation. From the photon energy dependence normal emission spectra, we observed an intermolecular energy-band dispersion about 0.2 eV for highest occupied molecular orbital (HOMO) band $\ensuremath{\pi}$ character. showed cosine curve, which...
The effect of the molecular orientation on electronic structure is studied Cu-phthalocyanine∕graphite system via film thickness dependences metastable-atom electron spectra and ultraviolet photoelectron spectra. We observed a decrease in vacuum-level position corresponding band-bending-like shift highest occupied state only for thick films where tilt angle increases gradually with thickness. These shifts are explained by electric dipoles produced gradient intermolecular interaction along...
The hole-vibration coupling of the highest occupied state in pentacene thin films on graphite is studied by high-resolution ultraviolet photoelectron spectroscopy. Vibration satellites film show a take-off-angle dependence, indicating that Franck-Condon principle not strictly satisfied this system. They are more intense than gas phase and vibrational energy slightly lower phase. This demonstrates reorganization larger estimated from spectrum free molecules. Furthermore, it pointed out...