Article
Chemistry, Multidisciplinary
Ruizhe Yang, Matthew Benner, Zipeng Guo, Chi Zhou, Jun Liu
Summary: Dynamic Schottky direct-current (DC) generators show great potential for energy harvesting, but the lack of understanding of DC generation in conducting polymer-based generators has hindered their applications. A high-performance, flexible Schottky DC generator demonstrated large current density and scaled-up DC output, inheriting flexibility from the long-chain polymer concept and showing promise for next-generation wearable devices.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Energy & Fuels
Xudong Li, Jinfeng Zhang, Kai Dai, Ke Fan, Changhao Liang
Summary: In this study, a Sn/Cd-3(C3N3S3)(2) (CdTMT) composite was developed to achieve nearly 99% selectivity in the conversion of CO2 to CO. The presence of metal Sn on the surface of CdTMT forming a Schottky heterojunction significantly enhanced the separation efficiency of photogenerated carriers and boosted the photocatalytic activity for CO2 reduction by about 3.7 times compared to pure CdTMT.
Review
Nanoscience & Nanotechnology
Mesfin Eshete, Xiyu Li, Li Yang, Xijun Wang, Jinxiao Zhang, Liyan Xie, Linjie Deng, Guozhen Zhang, Jun Jiang
Summary: Studying charge kinetics is crucial for optimizing quantum efficiency in photocatalysts. The design of photocatalysts has become more complex, requiring a detailed understanding of charge dynamics in heterojunctions. This article focuses on the steering of charge kinetics by modulating charge energy states in semiconductor-metal-interface-based heterogeneous photocatalysts, and presents general principles for their design and construction. Recent advances in interfacing semiconductors with graphene, carbon quantum dots, and graphitic carbon nitride are discussed, along with their limitations and potential future developments.
Article
Engineering, Electrical & Electronic
Richard O. Ocaya, Ibrahim Erol, Abdullah G. Al-Sehemi, Aysegul Dere, Ahmed A. Al-Ghamdi, Fahrettin Yakuphanoglu
Summary: In this article, a new Schottky diode based on a transparent conducting polymer PFPAMA doped with 5% ZnO is presented. The presence of PFPAMA suppresses interface states and improves the performance of the diode. The performance of the diode can be optimized by controlling the ZnO doping.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Energy & Fuels
Liyan Chen, Hao Lin, Zhaolang Liu, Taojian Wu, Yicong Pang, Pingqi Gao, Wenzhong Shen
Summary: The paper demonstrates a new method to extract specific contact resistance from the minority carrier collection region by using the expanded Cox and Strack method. By utilizing technology computer-aided design and a double equivalent circuit model, the method can separate electron and hole current densities, effectively determining the corresponding resistance for both polarities. The effectiveness of this improved method is further validated through experimental examples, establishing a general method for accurately extracting specific contact resistance in DFHJ silicon solar cells.
Article
Optics
Huang Hui-Lin, Huang Jing, Shi Quan
Summary: This paper proposes a method for extracting millimeter wave equivalent circuit model parameters for Schottky diodes. Parameters such as pad capacitance, feedline inductance, and parasitic resistance are determined using various test structures. Excellent fit between measured and simulated S-parameters is achieved in the frequency range of 1 to 40 GHz for GaAs Schottky diode.
JOURNAL OF INFRARED AND MILLIMETER WAVES
(2021)
Article
Engineering, Electrical & Electronic
M. Aldrigo, M. Dragoman, N. Pelagalli, E. Laudadio, L. Zappelli, S. Iordanescu, D. Vasilache, A. Dinescu, L. Pierantoni, P. Stipa, D. Mencarelli
Summary: This article presents a two-atom-thick diode based on 2-D materials for microwave detection, showing different behaviors in different voltage ranges with good performance. Through advanced quantum simulations and experimental characterization, a rigorous equivalent circuit model is established to facilitate the design of complex microwave front ends.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2022)
Review
Chemistry, Multidisciplinary
Basudeb Dutta, Shibashis Halder
Summary: Fabricating diodes with different materials is a trending research direction, and recently organic materials and metal complexes containing organic ligands are preferred for making Schottky barrier diodes. The utilization of Schiff-base compounds and Schiff base containing metal complexes in diode fabrication is highly appreciated due to their simplicity, cost-effectiveness, and tunability of optical properties. Proper molecular structure design is crucial for the conducting properties of the materials, and these materials can be utilized for making active electronic devices and photosensitive diodes. This review of research articles on Schottky diodes based on Schiff bases and metal complexes with Schiff base ligands is considered helpful for researchers in this field.
Article
Chemistry, Physical
V. V. Volkov, V. Sidey, A. Naumov, N. A. Kolyshkin, A. Kosyakov, I. N. Nekrylov, N. Yu Brezhnev, A. Yu Zavrazhnov
Summary: This article investigates the preparation and stabilization of new high-temperature semiconductor phases A (III) - B (VI) in the Ga-S system, identifying four polymorphic Ga2S3 phases and confirming the equilibrium of the gamma-Ga2+delta S3 phase. The study combines various methods of differential thermal analysis, microstructural analysis, and powder X-ray diffractometry to provide reliable results.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Analytical
Stefan Moench, Richard Reiner, Michael Basler, Daniel Grieshaber, Fouad Benkhelifa, Patrick Waltereit, Ruediger Quay
Summary: A three-phase GaN-based motor inverter IC with integrated phase current mirror sensors, a temperature sensor, and an amplifier was presented and tested. The IC operated successfully with space-vector pulse width modulation, and a bidirectional measurement capability was verified. The capacitive coupling from the three switch-nodes to the substrate was analyzed and experimentally confirmed to have four discrete semi-floating substrate voltage levels.
Article
Nanoscience & Nanotechnology
M. Bharathi, K. N. Anuradha, M. V. Murugendrappa
Summary: A series of nanocomposites with different weight percentages (10%, 20%, 30%, 40%, and 50%) of Praseodymium Calcium Manganite Oxide (Pr0.75Ca0.25MnO3) (PCM) nano manganites in polypyrrole (PPy) were synthesized via chemical polymerization technique. The nanocomposites exhibited crystalline nature and spherical particle morphology. Fourier Transform Infra-Red Spectroscopy (FTIR) analysis revealed improved conjugation due to chemical interaction between PPy and PCM particles. AC conductivity measurements showed Jonscher's power law behavior at higher frequencies. The study also investigated the frequency and temperature-dependent dielectric properties and impedance behavior of the nanocomposites.
DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES
(2023)
Article
Automation & Control Systems
Samuel S. Queiroz, Demercil de S. Oliveira, Paulo P. Praca, Luis H. S. C. Barreto
Summary: This study investigates the generalized cascaded full-bridge concept, which aims to reduce stress on semiconductors and provide flexible design options. The structures introduced have the potential to improve performance in high-power applications by reducing losses in power semiconductors and the number of devices required.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Physics, Applied
Suguri Uchida, Takuto Soma, Miho Kitamura, Hiroshi Kumigashira, Akira Ohtomo
Summary: This study reports the growth of SnO films on specific substrates and demonstrates the significant impact of surface treatment on optical transparency, resulting in enhanced visible transmittance of the films. This enhancement is attributed to the suppression of midgap states near the film surface.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Shuxin Zhang, Tatsuya Yajima, Takuto Soma, Akira Ohtomo
Summary: In this study, two polymorphs of MoO3 were epitaxially grown on the (100) plane of cubic perovskites using pulsed-laser deposition. The impacts of Li-ion intercalation on each phase were investigated through electrochemical testing. The alpha-MoO3 films transformed to an amorphous phase after a single electrochemical cycle, while the beta-MoO3 films showed reversible cyclic voltammogram against repeated electrochemical cycles.
APPLIED PHYSICS EXPRESS
(2022)
Article
Multidisciplinary Sciences
Hideki Matsuoka, Tetsuro Habe, Yoshihiro Iwasa, Mikito Koshino, Masaki Nakano
Summary: In this study, a proximity-induced ferromagnetic/ferrovalley ground state with spontaneous spin-valley polarization was demonstrated in a V5Se8/NbSe2 heterostructure using Hall effect measurements. This reveals the emergence of a new quantum electronic ground state at a van der Waals (vdW) interface.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Applied
Junichi Shiogai, Atsushi Tsukazaki
Summary: In this study, a freestanding single-crystalline FeSe membrane was prepared using a water-soluble Sr3Al2O6 sacrificial layer as a growth template. The FeSe membrane was fully relaxed with minimal degradation of its structural properties during the lift-off process. The freestanding FeSe membrane exhibited superconductivity below 4.2 K, while it was not observed in a compressed thin-film form.
APPLIED PHYSICS LETTERS
(2023)
Letter
Physics, Multidisciplinary
Minoru Kawamura, Masataka Mogi, Ryutaro Yoshimi, Takahiro Morimoto, Kei S. Takahashi, Atsushi Tsukazaki, Naoto Nagaosa, Masashi Kawasaki, Yoshinori Tokura
Summary: Adiabatic charge pumping is observed in a thin-film magnetic heterostructure of topological insulators, confirming the theoretical prediction of topological magnetoelectric effect. The pumped charge is proportional to the surface Hall conductivity, providing clues for its direct observation.
Article
Chemistry, Inorganic & Nuclear
Zaichun Sun, Shaoyong Qin, Daichi Oka, Huijuan Zhang, Tomoteru Fukumura, Yuji Matsumoto, Bingchu Mei
Summary: Semitransparent and homogeneous bismuth oxychloride (BiOCl) thin films with (001) preferred orientation were synthesized on polycrystalline Sn:In2O3-glass substrates by mist chemical vapor deposition. The films showed photocathodic activity even under near-ultraviolet light within the band gap due to the in-gap states induced by oxygen vacancies. Higher synthesis temperatures resulted in a significant increase of photocurrent density under ultraviolet light. The longer lifetime of photocarriers led to an increase of internal quantum efficiency, while the larger band-edge absorption significantly contributed to the higher external quantum efficiency.
INORGANIC CHEMISTRY
(2023)
Article
Physics, Applied
Kohei Fujiwara, Junya Ikeda, Shun Ito, Atsushi Tsukazaki
Summary: Solid-liquid interfaces composed of functional inorganic materials and liquid electrolytes exhibit interesting responses when an electric bias is applied. By using an electric-double-layer device on a thin-film channel of magnetic Weyl semimetal Co3Sn2S2 with an ionic liquid gate electrolyte, it is shown that the thickness of the conducting channel can be effectively reduced with a negative gate voltage. This finding allows for the examination of the thickness dependence of the anomalous transport properties of Co3Sn2S2 in a single sample.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Masamichi Negishi, Kohei Fujiwara, Atsushi Tsukazaki
Summary: Pulsed-laser deposition is a widely used method to fabricate complex oxide thin films, and film composition is regulated by various conditions. This study reports an experimental scheme to tune the composition ratio in Mg-Ir-O films fabricated by pulsed-laser deposition. By examining different parameters, a wide range of composition ratio was regulated in the films, and a spinel-related crystalline phase was discovered in the Mg-rich compositions.
Article
Multidisciplinary Sciences
Kohei Fujiwara, Yasuyuki Kato, Hitoshi Abe, Shun Noguchi, Junichi Shiogai, Yasuhiro Niwa, Hiroshi Kumigashira, Yukitoshi Motome, Atsushi Tsukazaki
Summary: Amorphous semiconductors are widely used in electronic and energy-conversion devices. This study reveals that the short-range crystalline order in amorphous Fe-Sn films contributes to anomalous electrical and magneto-thermoelectric properties. This finding sheds light on the topology of amorphous materials and may enable the realization of functional topological amorphous electronic devices.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Motoki Osada, Kohei Fujiwara, Tsutomu Nojima, Atsushi Tsukazaki
Summary: The nickelate superconductor with infinite NiO2 layer was synthesized by reducing the perovskite precursor phase through topochemical reduction. By increasing the reduction temperature, La1-xSrxNiO2 films transformed from the insulating state to the superconducting state, with a maximum onset superconducting transition temperature T onset c of about 14K at x = 0.20. The electrical conduction in NiO2 planes is found to be a sensitive parameter for optimizing the reduction state. The systematic optimization of reduction temperature resulted in an expanded superconducting dome in the phase diagram with higher T onset c and wider x range (0.12 x 0.28) compared to previous reports.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Kota Matsumoto, Hideyuki Kawasoko, Eiji Nishibori, Tomoteru Fukumura
Summary: A reversible switching of room-temperature electrical resistivity was demonstrated in a layered nickelate Sr2.5Bi0.5NiO5, which undergoes unique crystalline phase changes between different structures. This phenomenon has not been reported in transition metal oxides despite their extensive studies on electrical conduction.
Article
Chemistry, Inorganic & Nuclear
Sailaja S. Sunkari, Abhineet Verma, Om Pandey, Shraddha Gupta, Masanori Wakizaka, Shinya Takaishi, Hideyuki Kawasoko, Tomoteru Fukumura, Masahiro Yamashita
Summary: The first slow magnetic relaxation in a ferromagnetic Cu(II) chain compound, Cu(dipic)(OH2)(2), induced by a phonon bottleneck effect under a magnetic field of 0.6 T, with a relaxation time of 2.2 s at 2.8 K, was observed.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Jiyang Huang, Daichi Oka, Yasushi Hirose, Masamichi Negishi, Tomoteru Fukumura
Summary: We grew thin films of Ti0.95Co0.05O2-δ, a room-temperature ferromagnetic semiconductor, on rigid and flexible glass substrates using TiO2 seed layers. The thin films exhibited a preferred (101) orientation and large crystallographic domains of around 50 μm in lateral size, showing clear ferromagnetic hysteresis loops at 300 K. The films also had high electrical conductivity and transparency, allowing for electrical and optical detection of the ferromagnetic signal through the anomalous Hall effect and magneto-optical effect, respectively. Interestingly, flatter films with larger domains were obtained on flexible glass substrates, leading to higher conductivity and larger anomalous Hall signals comparable to epitaxial thin films.
Article
Materials Science, Multidisciplinary
Taiki Taguchi, Katsuaki Sugawara, Hirofumi Oka, Tappei Kawakami, Yasuaki Saruta, Takemi Kato, Kosuke Nakayama, Seigo Souma, Takashi Takahashi, Tomoteru Fukumura, Takafumi Sato
Summary: We discovered that monolayer 1T-NbTe2 is a new class of two-dimensional transition-metal dichalcogenide (TMD) with a star-of-David lattice similar to bulk TaS2 and isostructural monolayer NbSe2. It exhibits a metallic ground state characterized by the sparsely occupied star-of-David lattice with a lattice periodicity of (19x19). By using various techniques, we found that the hidden Fermi-surface nesting and associated CDW formation are the primary causes for this unique correlated metallic state without a Mott gap.
Article
Materials Science, Multidisciplinary
Takuto Soma, Kohei Yoshimatsu, Koji Horiba, Hiroshi Kumigashira, Akira Ohtomo
Summary: The oxide superconductor Li1-xNbO2, with two-dimensional NbO2 layers, exhibits 2D superconductivity and large anisotropy in the upper critical field. The temperature-independent anisotropy suggests single-band superconductivity, which is different from other materials with similar structures. The study also reveals a narrow and correlated single band in the 2D NbO2 layers of Li1-xNbO2, similar to the superconductivity in cuprates.
