Article
Physics, Condensed Matter
Adeeba Naz, Shatha A. Aldaghfag, Muhammad Yaseen, Mehwish K. Butt, Muhammad Kashif, Muhammad Zahid, Shanza Mubashir, H. H. Somaily
Summary: In this study, the FP-LAPW method based on DFT was used to investigate the effects of Ce doping on the band structure and optical properties of BaTiO3 compound. The results revealed that Ce doping can transform Ba1-xCexTiO3 from an indirect band gap semiconductor to a direct band gap semiconductor, and the band gap width decreases with the increase of Ce concentration. Furthermore, the optical behavior of Ba1-xCexTiO3 compounds was evaluated, and it was found that Ce doping could make BaTiO3 compound promising for optical and optoelectronic devices.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
M. Rahman, M. Kamruzzaman, J. A. Zapien, R. Afrose, T. K. Anam, M. N. H. Liton, M. A. Helal, M. K. R. Khan
Summary: Elemental doping is an efficient strategy to modulate different properties of semiconductors, and this study investigates the conversion from n-type to p-type and band gap modulation of ZnO using both theoretical and experimental approaches. The results show that silver (Ag) and silver-lithium (Ag-Li) doping can create acceptor levels in ZnO, making them promising dopants for generating p-type ZnO. Significant changes in photoconductivity and optical properties are also observed. This study helps in understanding the doping mechanism in ZnO and provides insights for the fabrication of p-type ZnO for advanced electronic and opto-electronic applications.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Ravindra Jangir, Velaga Srihari, Ashok Kumar Bhakar, Mangla Nand, Dinesh Kumar Shukla, Shambhu Nath Jha, Tapas Ganguli
Summary: This study investigates the suitability of Ni-doped alpha-GaCrO3 as a hole transport layer (HTL) material. The research finds that Ni doping improves the electrical properties of the material, resulting in better charge carrier transport. Therefore, Ni-doped alpha-GaCrO3 could be a promising HTL material.
ACS APPLIED ENERGY MATERIALS
(2022)
Review
Chemistry, Physical
Songyu Li, Yang Ma, Nabonswende Aida Nadege Ouedraogo, Famin Liu, Congya You, Wenjie Deng, Yongzhe Zhang
Summary: This review summarizes various strategies for p-/n-type modulation of TMDCs, including controlling intrinsic defects, doping, surface charge transfer, chemical intercalation, electrostatic modulation, and dielectric interface engineering. The mechanisms and comparisons of these strategies are analyzed, along with a discussion of their device applications in electronics and optoelectronics. Challenges and outlooks for p-/n-type modulation of TMDCs are presented for future research references.
Article
Environmental Sciences
Sarfraj Ahmed, Sudip K. Sinha
Summary: The development of metal oxide semiconductor materials has improved the performance of gas sensors in terms of selectivity, sensitivity, and response time. To enhance selectivity and minimize power consumption, nanoparticle-based p-type semiconductor materials are being developed.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Inorganic & Nuclear
Yu-Hsuan Su, Wei-Liang Chen, Hye Ryung Byun, Yu-Fu Zhang, Min-Rui Zhuang, Yu-Cih Lin, Chung-Kai Chang, Po-Yuan Wang, Che-Cheng Lin, Kuang- Lin, Hsin-Kuan Liu, Min-Kai Lee, Joon Jang, Yu-Ming Chang, Kuei-Fang Hsu
Summary: A new copper indium selenide with an orthorhombic crystal structure was synthesized at 800 degrees C. It emits intense photoluminescence at 657 nm and exhibits a direct band gap with an energy close to the photoluminescence position. The compound also shows n-type conductivity and strong nonlinear third-harmonic generation.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Chioma Vivian Ezeh, Kingsley O. Egbo, Jamaal-Deen Musah, Kin Man Yu
Summary: Gallium oxide (Ga2O3) has attracted significant interest for its wide bandgap and unique properties. Researchers have successfully modified the electronic bands of Ga2O3 through alloying with NiO to achieve p-type conducting Ga2O3-NiO thin films. The films exhibited different structural properties and optical behaviors depending on the Ni content. The p-type alloy films with a high concentration of Ni vacancies showed a wide tunability of bandgap and sub-gap absorption.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Jiajia Zhang, Yu Zhong
Summary: This study reveals the origins of p-doping and nonradiative recombination in Sn-based perovskites. The authors find that p-doping is dominated by Cs vacancies, while I vacancies are the main nonradiative recombination centers. The results emphasize the importance of minimizing the formation of Cs and I vacancies for achieving optimal device performance.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
Jueli Shi, Jiaye Zhang, Lu Yang, Mei Qu, Dong-Chen Qi, Kelvin H. L. Zhang
Summary: Wide bandgap oxide semiconductors are a unique class of materials with properties of electrical conductivity and optical transparency, widely used in optoelectronics. Recent research focuses on understanding the materials physics and designing new high-performing TFT devices based on oxide semiconductors.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Physical
Zeyu Chi, Corinne Sartel, Yunlin Zheng, Sushrut Modak, Leonid Chernyak, Christian M. Schaefer, Jessica Padilla, Jose Santiso, Arie Ruzin, Anne-Marie Goncalves, Jurgen von Bardeleben, Gerard Guillot, Yves Dumont, Amador Perez-Tomas, Ekaterine Chikoidze
Summary: The room temperature hole conductivity of β-Ga2O3 was achieved by growing high-quality films on a sapphire substrate. The conductivity was significantly enhanced by zinc doping with low activation energy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Inorganic & Nuclear
Yumei Jiang, Yuting Zhang, Juanjuan Xing, Yibin Hu, Xinxin Yang, Jiye Zhang, Kai Guo, Jun Luo
Summary: The concept of phonon-glass, electron-crystal has led to the development of a new wide-band-gap semiconductor SrFCuTe with low p-type conductivity and thermal conductivity. Substituting Na for Sr can significantly improve the electrical transport properties but also increase the electronic thermal conductivity. This study demonstrates that rational performance manipulation can greatly enhance the thermoelectric performance of wide-band-gap semiconductors.
JOURNAL OF SOLID STATE CHEMISTRY
(2021)
Article
Engineering, Electrical & Electronic
Soungmin Bae, Yoon-Gu Kang, Kodai Ichihashi, Mohammad Khazaei, Varghese Swamy, Myung Joon Han, Kee Joo Chang, Ken-ichi Shudo, Hannes Raebiger
Summary: This study suggests that strain engineering can release trapped hole carriers in gallium nitride materials, solving the challenge of p-type doping. Additionally, the photoluminescence spectrum of magnesium impurities can be tuned by lattice strain, allowing for efficient control of gallium nitride light emission.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Physical
Yaoqiao Hu, Darrell Schlom, Suman Datta, Kyeongjae Cho
Summary: Recent research on high mobility p-type oxides has found some promising candidates, but few have been experimentally proven to have high p-type conductivity due to limited p-type doping. This work reports on a-Ta2SnO6, an amorphous phase oxide, which has a shallow valence band edge (VBE) allowing high p-type doping without oxygen vacancy defects. This is in contrast to the crystalline phase, c-Ta2SnO6, which has a deep VBE and low p-type dopability due to strong electrostatic interaction between Ta5+ and Sn-5s lone-pair electrons.
APPLIED SURFACE SCIENCE
(2023)
Article
Energy & Fuels
Yaju Wei, Guoqiang Yu, Guohui Luo, Wang Fu, Wuqi Liu, Tao Wang, Haonan Xu, Xiaoping Wu, Lingbo Xu, Ping Lin, Xiaodong Zhu, Xuegong Yu, Peng Wang, Can Cui
Summary: In this study, the oxidation states of solution-processed MoO3-x were tuned by doping Nb5+ to improve its hole-selective contact performance with silicon. The contact resistivity between the MoO3-x film and p-type silicon decreased from 161.1 to 62.9 mΩ·cm^2 and the effective carrier lifetime increased from 165.4 to 391.0 μs with the optimal doping concentration of 5%. Similarly, the doping of Ta5+ or V5+ in MoO3-x improved the passivated contact performance with silicon, with the former increasing the concentration of oxygen vacancies and the latter reducing it. The solar cell with the structure of Ag/MoO3-x:Nb/p-Si achieved a conversion efficiency of 18.37%, which is the highest reported for solution-processed MoO3-x/silicon heterojunctions. This work demonstrates a feasible strategy of doping to tune hole selectivity in MoO3-x for high-efficiency solar cells and other optoelectronic device applications.
Article
Materials Science, Multidisciplinary
Xia Qiu, Wangping Xu, Weixiang Kong, Xiaoliang Xiao, Rui Wang, Jing Fan, Xiaozhi Wu
Summary: Recently, a centimeter-scale monolayer MoSi2N4 with excellent ambient stability was successfully synthesized. However, its indirect band gap semiconductor property hinders its wide application. In this study, we systematically investigated the stability and optoelectronic properties of two new alpha(1)-phase monolayers (MoSi2Sb4 and WSi2Sb4) and a new family of alpha(2)-phase monolayer MSi(2)Z(4) (M = Mo, W; Z = P, As, Sb) using first-principles calculations. We found that all these monolayer structures showed high structural stability, with the alpha(2)-phase structures being more stable than the alpha(1)-phase structures. Moreover, all of them possessed direct band gaps and exhibited fascinating optical absorption efficiencies from infrared to visible light. The high hole mobility demonstrated their potential applications in photoelectric devices, while alpha(2)-MoSi2P4 showed a desirable power conversion efficiency of 20.3%. Spin-orbit coupling played a crucial role in exploring the optoelectronic properties of the MSi(2)Z(4) ternary compounds. These new ternary monolayer structures can effectively expand the 2D materials family and offer promising potential candidates for optoelectronic applications.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Nanoscience & Nanotechnology
Tomoyuki Yamasaki, Ryosei Takaoka, Soshi Iimura, Junghwan Kim, Hidenori Hiramatsu, Hideo Hosono
Summary: Ion migration induced resistive switching holds great promise for applications such as ReRAM and neuromorphic transistors. In this study, reversible resistive switching characteristics were observed in rare-earth oxyhydrides (REHxO(3-x)/2) induced by field insertion/extraction of H-. The ratio of H-/O2- in the films greatly affects the resistive switching response, hysteresis, and switching voltage.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Xinyi He, Jinshuai Chen, Takayoshi Katase, Makoto Minohara, Keisuke Ide, Hidenori Hiramatsu, Hiroshi Kumigashira, Hideo Hosono, Toshio Kamiya
Summary: This study reports the direct growth of metastable cubic (Sn1-xCax)Se films alloyed with CaSe, which have a wider bandgap and higher carrier mobility compared to Sn1-xPbxSe films. The results reveal the potential of high mobility (Sn1-xCax)Se films for semiconductor device applications.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Inorganic & Nuclear
Akihiro Shiraishi, Shigeru Kimura, Xinyi He, Naoto Watanabe, Takayoshi Katase, Keisuke Ide, Makoto Minohara, Kosuke Matsuzaki, Hidenori Hiramatsu, Hiroshi Kumigashira, Hideo Hosono, Toshio Kamiya
Summary: The study focuses on the synthesis and optoelectronic properties of high phase-purity bulk polycrystals of KCoO2-type layered nitrides AETMN2 (AE= Sr, Ba; and TM= Ti, Zr, Hf). The materials exhibit n-type semiconductor behavior with different optical band gaps, and BaHfN2 shows nondegenerated electron conduction along with weak ferromagnetic behavior. Density functional theory calculations are used to explain the mechanism of carrier generation and impurity incorporation in the materials.
INORGANIC CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Zexuan Zhang, Yusuke Hayashi, Tetsuya Tohei, Akira Sakai, Vladimir Protasenko, Jashan Singhal, Hideto Miyake, Huili Grace Xing, Debdeep Jena, YongJin Cho
Summary: Successful homoepitaxial growth of N-polar AlN has been achieved on large-area N-polar AlN templates using MBE. Al-assisted cleaning enables the epitaxial film to maintain N-polarity, resulting in a smooth, defect-free surface and suppression of nonradiative recombination centers.
Article
Physics, Applied
Keisuke Ide, Naoto Watanabe, Takayoshi Katase, Masato Sasase, Junghwan Kim, Shigenori Ueda, Koji Horiba, Hiroshi Kumigashira, Hidenori Hiramatsu, Hideo Hosono, Toshio Kamiya
Summary: In this study, LEDs were fabricated on glass substrates using amorphous oxide semiconductor materials as emission layers. Rare-earth-doped AOS films were employed, and the LEDs emitted clear red, green, and pink luminescence even in the ambient environment. Resonance photoelectron spectroscopy revealed different emission mechanisms for each rare-earth dopant. This study provides opportunities for the advancement of flexible display technologies in harsh environments.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Kota Hanzawa, Jumpei Matsumoto, Soshi Iimura, Yoshimitsu Kohama, Hidenori Hiramatsu, Hideo Hosono
Summary: The electronic transport properties of a highly hydrogen-substituted SmFeAsO epitaxial film with high critical-temperature were investigated under high magnetic fields. The results showed that the film had high potential for superconducting electromagnets and cables due to its high critical temperature, high critical current density, and small anisotropic parameter.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Physical
Naoto Kawaguchi, Kiyou Shibata, Teruyasu Mizoguchi
Summary: Graphite intercalation compounds (GICs) are formed by inserting various atoms and molecules between the layers of graphite. The formation energies of GICs with different crystal structures and atoms were investigated using a van der Waals density functional method, revealing stable GICs that have not been reported before. Additionally, potential superconductivity and charge density wave were predicted for certain GICs, providing insights into their unique physical properties.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Po-Yen Chen, Kiyou Shibata, Katsumi Hagita, Tomohiro Miyata, Teruyasu Mizoguchi
Summary: A machine learning model was constructed to predict the partial density of states (PDOS) of the ground-state carbon s- and p-orbitals from C K-edge spectra. The model was also tested for extrapolation prediction of PDOS for larger molecules, and excluding tiny molecules improved the extrapolation performance. Additionally, the PDOS prediction for spectra with noise can be enhanced by using smoothing preprocess and training with specific noise data, enabling the application of the prediction model to experimental data.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Zhongxu Hu, Mari Hiramatsu, Xinyi He, Takayoshi Katase, Terumasa Tadano, Keisuke Ide, Hidenori Hiramatsu, Hideo Hosono, Toshio Kamiya
Summary: We demonstrated a reversible 2D-3D crystal structure transition and thermal conductivity switching in (Sn1-xPbx)S bulk polycrystals. The direct phase boundary between the 2D and 3D structures does not exist under thermal equilibrium conditions, but by using a non-equilibrium synthesis process, the phase boundary can be formed. This transition has potential applications in developing thermal management materials.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Kota Hanzawa, Hidenori Hiramatsu
Summary: LaWN3 epitaxial thin films were successfully grown on α-Al2O3 (0001) substrates using a multi-cathode RF magnetron sputtering gun system with metal targets and nitrogen gas. The films exhibited n-type degenerate semiconducting behaviors, an enlarged optical band gap, and superconductivity at 0.73 K. However, they did not show the predicted ferroelectric properties due to off-stoichiometry. Alternative growth processes are needed to decrease carrier density and achieve ferroelectricity.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Physics, Applied
Kazuki Mitsui, Zhongxu Hu, Kota Hanzawa, Takayoshi Katase, Hidenori Hiramatsu, Akira Saitoh
Summary: This study reports on the electrical conduction properties of iron oxide-containing bismuth sesquioxide borate glasses, which are not toxic and exhibit ohmic transport in the temperature range of 100-400 degrees C. The dominant carrier is the electron, as supported by the Hall and Seebeck coefficients. The glass can function as a glass thermistor for temperatures between 100-400 degrees C.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Dong-Hwan Yang, Yu-Seong Chu, Odongo Francis Ngome Okello, Seung-Young Seo, Gunho Moon, Kwang Ho Kim, Moon-Ho Jo, Dongwon Shin, Teruyasu Mizoguchi, Sejung Yang, Si-Young Choi
Summary: Point defects are common in two-dimensional materials and can be identified through direct visualization and statistical inspection, which are correlated with physical phenomena. Deep learning-based platforms combined with atomic structural imaging provide an intuitive and precise way to analyze point defects and gain insight into the defect-property correlation in two-dimensional materials.
MATERIALS HORIZONS
(2023)
Article
Physics, Multidisciplinary
Katsuaki Nakazawa, Yuhki Tsukada, Shin-ichi Amma, Kazutaka Mitsuishi, Kiyou Shibata, Teruyasu Mizoguchi
Summary: The study observed the phase separation process of amorphous glass in initial and intermediate stages, revealing specific changes in the phase-separated structures. The results indicate that the characteristic changes in phase-separated structures are attributed to the multimetastability of the amorphous phase.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Engineering, Electrical & Electronic
Ryotaro Miyake, Zenya Nagata, Kenta Adachi, Yusuke Hayashi, Tetsuya Tohei, Akira Sakai
Summary: Brain-inspired computing systems, which emulate the activity of biological synapses and neurons, have the potential to solve the von Neumann bottleneck. This study presents the fabrication of four-terminal memristive devices using epitaxial thin films of TiO2-x, and explores their capability to implement synaptic functions through the two-dimensional variation of oxygen vacancy distribution in the film. The results demonstrate the remarkable versatility of the four-terminal device for implementing diverse and complex functions of artificial synapses on a single memristive passive element.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Kaiwen Li, Atsushi Shimizu, Xinyi He, Keisuke Ide, Kota Hanzawa, Kosuke Matsuzaki, Takayoshi Katase, Hidenori Hiramatsu, Hideo Hosono, Qun Zhang, Toshio Kamiya
Summary: In this study, the intrinsic physical properties of polycrystalline Zn3N2 thin films were investigated by suppressing donor impurities. It was found that grain boundary scattering significantly affected the mobility in this nondegenerate Zn3N2 thin film. The mobility of this film, reaching 340 cm(2) V-1 s(-1), was comparable to epitaxial thin films, indicating its potential as a transistor active layer material.
ACS APPLIED ELECTRONIC MATERIALS
(2022)