Article
Chemistry, Physical
Yohei Uemura, Ahmed S. M. Ismail, Sang Han Park, Soonnam Kwon, Minseok Kim, Hebatalla Elnaggar, Federica Frati, Hiroki Wadati, Yasuyuki Hirata, Yujun Zhang, Kohei Yamagami, Susumu Yamamoto, Iwao Matsuda, Ufuk Halisdemir, Gertjan Koster, Christopher Milne, Markus Ammann, Bert M. Weckhuysen, Frank M. F. de Groot
Summary: In this study, the photoexcited state of a hematite thin film was investigated using X-ray absorption spectroscopy, and the 200 fs decay time of the hole state in the valence band was observed.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Ludiane Lima, Lucas de S. Caldas, Astrid Ali, Jade Barreto, Roberto Freitas, Aline Mazzarella, Guilherme Felix, Victor Carozo, Fernando Stavale
Summary: The research discovered that ultrathin ZnO films on Ag substrates exhibit well-defined stoichiometry and crystal phases, with Raman spectroscopy showing a substantial enhancement of Raman combination modes. The electronic and structural properties of finite-size films play a significant role in their vibrational properties, providing clues for understanding ZnO nanostructures.
Article
Nanoscience & Nanotechnology
Finn Zahari, Richard Marquardt, Matthias Kallaene, Ole Gronenberg, Christoph Schlueter, Yury Matveyev, Georg Haberfehlner, Florian Diekmann, Alena Nierhauve, Jens Buck, Arndt Hanff, Gitanjali Kolhatkar, Gerald Kothleitner, Lorenz Kienle, Martin Ziegler, Juergen Carstensen, Kai Rossnagel, Hermann Kohlstedt
Summary: Memristive devices are being developed as non-volatile memory elements to enhance computing capabilities. Interface-based memristive devices are promising for emulating synaptic functionalities in neuromorphic circuits. A device composed of Nb/NbOx/Al2O3/HfO2/Au demonstrates analog switching, no electro-forming, and high current-voltage non-linearity. Spectroscopic evidence and device modeling support the concept of memristive switching based on charge traps within HfO2.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Physical
Daniel Hemmeter, Ulrike Paap, Florian Maier, Hans-Peter Steinrueck
Summary: In this study, the surface composition and interfacial behavior of commercial [Rh(COD)(2)][TfO] in different ILs were investigated using ARXPS. The complex was found to undergo non-intact decomposition in these ILs, with the loss of COD ligands and depletion of the metal center from the IL/vacuum interface. Increasing the chain length of the aliphatic substituent on the imidazolium cation resulted in a more significant depletion, attributed to the higher surface affinity of the solvent cations with longer alkyl chains. The loss of COD ligands allowed in situ ligand substitution with TPPTS, leading to an increase in the surface concentration of Rh and the formation of a Schrock-Osborn-type catalyst.
Review
Chemistry, Multidisciplinary
Vishal Kumar, Nisika, Mukesh Kumar
Summary: Solar cell technologies have attracted significant attention due to their potential to meet global energy demand sustainably. Researchers are focusing on improving the efficiency of photovoltaic materials and developing advanced characterization tools to understand material properties in multiple dimensions. The recent advances in multidimensional characterization tools provide high spatial, energy, and temporal resolution to optimize material properties and device performance.
ENERGY & ENVIRONMENTAL SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Cesar D. D. Mendoza, F. L. Freire Jr
Summary: We investigated the interfacial electronic structure of single-layer graphene on a germanium substrate using UPS and XPS. The graphene was directly synthesized on (110) undoped Ge substrate via CVD. The study identified the main graphitic properties and showed that the Ge substrate affected the electronic structure of the graphene due to electronic coupling. The study also provided important information on the Schottky contact's nature and energy level alignments for potential integration of single-layer graphene on a Ge substrate with CMOS technology.
Article
Materials Science, Multidisciplinary
Zdenek Remes, Anna Artemenko, Egor Ukraintsev, Dhananjay K. Sharma, Maksym Buryi, Alexander Kromka, Stepan Potocky, Ondrej Szabo, Jaroslav Kulicek, Bohuslav Rezek, Ales Poruba, Julia Micova, Hua Shu Hsu
Summary: This study investigates the impact of hydrogen plasma treatment on the properties of ZnO surfaces, revealing significant alterations in surface properties before and after plasma treatment depending strongly on the electrical potential of the holder. Various analytical methods, including XPS, photoluminescence spectroscopy, AFM, and KPFM, are employed to analyze the effects on the surface properties.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2022)
Article
Chemistry, Physical
Yu Liang, Guanhua Zhang, Julong Sun, Chuanyao Zhou, Ziling Li, Yu Ye, Xueming Yang, Zefeng Ren
Summary: This study systematically investigates the carrier dynamics of MoS2 flakes using femtosecond time-resolved spectroscopic photoemission electron microscopy, and finds that the dynamics strongly depend on temperature and carrier density.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Christian T. Plass, Valentina Bonino, Maurizio Ritzer, Lukas R. Jager, Vicente Rey-Bakaikoa, Martin Hafermann, Jaime Segura-Ruiz, Gema Martinez-Criado, Carsten Ronning
Summary: The dynamics of color centers in quantum technology are influenced by the local environment, and a combined approach of X-ray fluorescence analysis and X-ray excited optical luminescence (XEOL) was used to study this relationship. The simultaneous acquisition of data revealed compositional and functional variations at the nanoscale, demonstrating the extraordinary capabilities of these techniques. The findings on cobalt doped zinc oxide nanowires showed an anticorrelation between the band edge emission of the zinc oxide host and the intra-3d cobalt luminescence, indicating two competing recombination paths. Time-resolved XEOL measurements also revealed two exponential decays of the cobalt luminescence, with the fast decay attributed to a recombination cascade within the cobalt atom.
Article
Chemistry, Multidisciplinary
Yuriy Dedkov, Junhao Zhou, Yefei Guo, Elena Voloshina
Summary: The growth of a high-quality complete graphene layer is successfully achieved for Ir(111) and Ru(0001) substrates using liquid ethanol as a precursor,which provides an easy, quick, and reproducible method to synthesize large-scale graphene on different metallic substrates.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Energy & Fuels
Mingli Liang, Weihua Lin, Qian Zhao, Jun Li, Lin Zhu, Brice Sarpi, Alexei Zakharov, Ivan G. Scheblykin, Tonu Pullerits, Yuran Niu, Sophie E. Canton, Kaibo Zheng
Summary: This study presents the first investigation of spatially resolved electronic structures in 2D LHP single-crystal flakes, with a focus on the contribution from the edge area. The results show a blueshift in the Pb 5d core-level peaks at the edge area compared to the interior area, which is attributed to surface restructuring induced by the release of mechanical strain.
Article
Chemistry, Physical
Zhengjun Wang, Nils Lenngren, Edoardo Amarotti, Albin Hedse, Karel Zidek, Kaibo Zheng, Donatas Zigmantas, Tonu Pullerits
Summary: The excited-state dynamics in CdSe QDs were investigated using two-color 2D electronic spectroscopy. It was found that the relaxation of high-energy electrons occurs with a time constant of 100 fs, while the states at the band edge rise within 700 fs. The excited-state absorption also rises with a similar time constant of 700 fs. This study challenges the previous interpretation of the excited-state absorption.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Multidisciplinary Sciences
Catharine Shipps, H. Ray Kelly, Peter J. Dahl, Sophia M. Yi, Dennis Vu, David Boyer, Calina Glynn, Michael R. Sawaya, David Eisenberg, Victor S. Batista, Nikhil S. Malvankar
Summary: The study demonstrates that amyloid proteins can efficiently transport charges at physiologically relevant potentials without the need for metal cofactors or large driving forces. The conductivity is attributed to a multistep hopping mechanism, with hole transport rate influenced by proton acceptors and proximity to tyrosines. Surprisingly, conductivity increases significantly upon cooling due to higher availability of proton acceptors.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Review
Chemistry, Multidisciplinary
Zachary N. Heim, Daniel M. Neumark
Summary: The liquid microjet technique developed by Faubel and co-workers has enabled the investigation of high vapor pressure liquids and solutions using high-vacuum methods. PES and TRPES have been successfully utilized to study the electronic properties and excited state dynamics of pure solvents and solute-solvent systems.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Physical
Teng-Fei Lu, Weibin Chu, Sraddha Agrawal, Zhihua Zhang, Oleg V. Prezhdo
Summary: Perovskite solar cells, as a promising technology for low-cost and high-efficiency photovoltaics, face challenges in stability and nonradiative losses. This study demonstrates that replacing part of the iodide in formamidinium lead iodide (FAPbI(3)) with pseudohalide anions can suppress nonradiative charge recombination, leading to increased charge carrier lifetime.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Instruments & Instrumentation
Ulf Zastrau, Karen Appel, Carsten Baehtz, Oliver Baehr, Lewis Batchelor, Andreas Berghauser, Mohammadreza Banjafar, Erik Brambrink, Valerio Cerantola, Thomas E. Cowan, Horst Damker, Steffen Dietrich, Samuele Di Dio Cafiso, Joern Dreyer, Hans-Olaf Engel, Thomas Feldmann, Stefan Findeisen, Manon Foese, Daniel Fulla-Marsa, Sebastian Goede, Mohammed Hassan, Jens Hauser, Thomas Herrmannsdoerfer, Hauke Hoeppner, Johannes Kaa, Peter Kaever, Klaus Knofel, Zuzana Konopkova, Alejandro Laso Garcia, Hanns-Peter Liermann, Jona Mainberger, Mikako Makita, Eike-Christian Martens, Emma E. McBride, Dominik Moeller, Motoaki Nakatsutsumi, Alexander Pelka, Christian Plueckthun, Clemens Prescher, Thomas R. Preston, Michael Roeper, Andreas Schmidt, Wolfgang Seidel, Jan-Patrick Schwinkendorf, Markus O. Schoelmerich, Ulrich Schramm, Andreas Schropp, Cornelius Strohm, Konstantin Sukharnikov, Peter Talkovski, Ian Thorpe, Monika Toncian, Toma Toncian, Lennart Wollenweber, Shingo Yamamoto, Thomas Tschentscher
Summary: The European XFEL's HED scientific instrument delivers intense ultrashort and coherently X-ray radiation, enabling groundbreaking experiments in extreme conditions of matter. Current research at HED includes investigating extreme states of matter using intense laser pulses or X-ray methods.
JOURNAL OF SYNCHROTRON RADIATION
(2021)
Article
Chemistry, Physical
Jiayi Tang, Okkyun Seo, David S. Rivera Rocabado, Takanori Koitaya, Susumu Yamamoto, Yusuke Nanba, Chulho Song, Jaemyung Kim, Akitaka Yoshigoe, Michihisa Koyama, Shun Dekura, Hirokazu Kobayashi, Hiroshi Kitagawa, Osami Sakata, Iwao Matsuda, Jun Yoshinobu
Summary: The absorption and diffusion of hydrogen in cube-shaped palladium nanoparticles were investigated using AP-XPS and DFT calculations. The study found a size dependence in the subsurface hydrogen absorption and proposed a model for the interaction between hydrogen and palladium nanoparticles.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Masahiro Sato, Yuki Imazeki, Takahito Takeda, Masaki Kobayashi, Susumu Yamamoto, Iwao Matsuda, Jun Yoshinobu, Yoshiaki Nakano, Masakazu Sugiyama
Summary: This study investigates the evolution of n-GaN surface geometric structure and band bending during H2O and O2 exposure using first-principles calculations and AP-XPS measurements. The results show upward band bending on O2-exposed surfaces above 3/4 ML and near flat-band condition on H2O-exposed surfaces with high supply rates.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Yohei Uemura, Ahmed S. M. Ismail, Sang Han Park, Soonnam Kwon, Minseok Kim, Hebatalla Elnaggar, Federica Frati, Hiroki Wadati, Yasuyuki Hirata, Yujun Zhang, Kohei Yamagami, Susumu Yamamoto, Iwao Matsuda, Ufuk Halisdemir, Gertjan Koster, Christopher Milne, Markus Ammann, Bert M. Weckhuysen, Frank M. F. de Groot
Summary: In this study, the photoexcited state of a hematite thin film was investigated using X-ray absorption spectroscopy, and the 200 fs decay time of the hole state in the valence band was observed.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Fumihiko Ozaki, Shunsuke Tanaka, Wataru Osada, Kozo Mukai, Masafumi Horio, Takanori Koitaya, Susumu Yamamoto, Iwao Matsuda, Jun Yoshinobu
Summary: In this study, the effects of gaseous hydrogen exposure on bare MoS2 and Pd-deposited MoS2 basal surfaces were investigated using ambient-pressure X-ray photoelectron spectroscopy. The results indicate that Pd deposition creates an activation site for the dissociation of molecular hydrogen on the inert MoS2 basal surface. Furthermore, hydrogen atoms spill over onto the MoS2 surface, modulating the electronic states of the MoS2 substrate.
APPLIED SURFACE SCIENCE
(2022)
Editorial Material
Nanoscience & Nanotechnology
Hiroshi Daimon
E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Isao Kagomiya, Tomohiro Hirano, Yutaro Yagi, Ken-ichi Kakimoto, Susumu Yamamoto, Iwao Matsuda
Summary: This study investigated the surface reaction mechanism of mixed conductive materials using operando X-ray photoelectron spectroscopy. The results showed that applying current from negative to positive can increase the number of active reaction sites, thereby improving oxygen evolution performance.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Hiroshi Daimon, Ikko Tanaka
Summary: The dependence of forward scattering peak intensity on Z and the value of alpha were discussed in this article. It was found that Z-dependence plays a significant role in elemental analysis.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Ryu Yukawa, Susumu Yamamoto, Ren Arita, Yuki Minami, Kohei Yamanoi, Kenichi Ozawa, Kazuyuki Sakamoto, Toshihiko Shimizu, Nobuhiko Sarukura, Iwao Matsuda
Summary: Time-resolved photoluminescence experiments on ZnO crystals reveal the presence of at least two origins with different decay times in the near-band edge emission, which are associated with crystal defects and crystallinity.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Falk Pabst, Sabrina Palazzese, Felix Seewald, Shingo Yamamoto, Denis Gorbunov, Sumanta Chattopadhyay, Thomas Herrmannsdoerfer, Clemens Ritter, Kati Finzel, Thomas Doert, Hans-Henning Klauss, Jochen Wosnitza, Michael Ruck
Summary: This paper reports the synthesis, crystal growth, structure, and complex magnetic properties of a new compound Pr3Fe3Sb7. It is found that Pr3Fe3Sb7 shows spontaneous magnetization and exhibits noncollinear ferromagnetic order below 380K. The compound also exhibits a spin-reorientation transition and antiparallel magnetization behavior. Finally, the compound shows metallic resistivity along the c axis, with a small anomaly observed.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yoshiaki Ishihara, Takanori Koitaya, Yuto Hamahiga, Wataru Sugimoto, Susumu Yamamoto, Iwao Matsuda, Jun Yoshinobu, Ryo Nouchi
Summary: This study reports on the successful induction and electrical detection of methane oxidation reaction at room temperature using IrO2 nanosheets. The electrical resistance of the atomically thin IrO2 nanosheet films decreases upon exposure to methane and disappears when simultaneously exposed to oxygen, indicating the oxidation of methane using lattice oxygen of the nanosheets. The ability of IrO2 nanosheets to oxidize methane down to 300 K is confirmed, making it an important example of monitoring chemical reactions using electrical resistance changes.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Physical
Fumihiko Ozaki, Shunsuke Tanaka, Younghyun Choi, Wataru Osada, Kozo Mukai, Mitsuaki Kawamura, Masahiro Fukuda, Masafumi Horio, Takanori Koitaya, Susumu Yamamoto, Iwao Matsuda, Taisuke Ozaki, Jun Yoshinobu
Summary: Sulfur vacancies on an MoS2 basal plane significantly affect device performance and catalytic activity. This study investigates the electronic states of sulfur vacancies using AP-XPS and density functional theory calculations. The results provide insights into the changes in electronic states induced by sulfur vacancy formation and offer guidance for sulfur vacancy engineering.
Article
Materials Science, Multidisciplinary
Sh Yamamoto, T. Fujii, S. Luther, H. Yasuoka, H. Sakai, F. Baertl, K. M. Ranjith, H. Rosner, J. Wosnitza, A. M. Strydom, H. Kuehne, M. Baenitz
Summary: This study investigates the microscopic magnetic properties, phase transition characteristics, and ground state of the compound Ce2Rh2Ga using Ga-69(,)71 nuclear quadrupole resonance (NQR) technology. The results show an unusual phase transition at around 130 K, indicating the presence of two crystallographically inequivalent Ga sites. Additionally, no magnetic or charge order is observed at temperatures below 0.3 K, and the temperature-dependent spin-lattice relaxation rate 1/T-1 exhibits distinct regimes.
Article
Materials Science, Multidisciplinary
Sh Yamamoto, D. Gorbunov, I. F. Diaz-Ortega, A. Miyata, T. Kihara, Y. Kotani, T. Nakamura, N. Mushnikov, A. Andreev, H. Nojiri, J. Wosnitza
Summary: The study found that TbFe5Al7 undergoes a magnetic transition at high magnetic fields, with Tb 4 f and Fe 3d magnetic moments simultaneously rotating to another easy-axis direction. The magnetic-anisotropy constant of TbFe5Al7 was determined by simulating the magnetization process at high fields.
Article
Nanoscience & Nanotechnology
M. Okawa, K. Akikubo, S. Yamamoto, I Matsuda, T. Saitoh
Summary: The temporal variations of valence states of alpha-YbAl1-xFexB4 crystals were experimentally examined in a nanosecond time-scale using time-resolved photoemission experiments with synchrotron radiation. The dynamics of valence fluctuations in the material are likely dominated by a picosecond or much faster time-scale, as indicated by the experimental results. The time-resolved measurement captured the trace of valence fluctuations at the time-resolution limit of synchrotron radiation.
E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY
(2021)
