Article
Chemistry, Physical
Ryuto Horie, Hiroyuki Nishinaka, Daisuke Tahara, Masahiro Yoshimoto
Summary: Alloying γ-Ga2O3 with γ-aluminum oxide effectively achieves lattice-matched growth and band gap engineering, leading to a band gap energy of 5.88 eV. The epitaxial growth of γ-(AlxGa1-x)2O3 on spinel substrates demonstrated limited dislocations and band gap engineering capabilities in the range of 5.0-6.0 eV, showing promise for wide band gap semiconductor applications in power switching devices and deep-ultraviolet optoelectronics.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Ray-Hua Horng, Dong-Sing Wuu, Po-Liang Liu, Apoorva Sood, Fu-Gow Tarntair, Yu-Hsuan Chen, Singh Jitendra Pratap, Ching -Lien Hsiao
Summary: In this study, monoclinic gallium oxide (beta-Ga2O3) epilayer was successfully grown on a sapphire substrate by MOCVD. Controlling the growth temperature, TEGa flow rate, and growth time improved the crystallization characteristics of the epilayers. However, it also increased the surface roughness of beta-Ga2O3 film. The growth mechanism and chemical reactions between TEGa and oxygen precursors were analyzed.
MATERIALS TODAY ADVANCES
(2022)
Article
Chemistry, Multidisciplinary
Asha Yadav, Bo Fu, Stephanie Nicole Bonvicini, Linh Quy Ly, Zhitai Jia, Yujun Shi
Summary: beta-Ga2O3 nanostructures with different morphologies, including nanowires, nanosheets, and nanorods, were successfully synthesized using thermally dewetted Au nanoparticles as catalysts. The growth of the nanostructures was found to be governed by different mechanisms, with the vapor-liquid-solid mechanism governing nanowire growth and the vapor-solid mechanism occurring in the growth of nanosheets and nanorods. The as-grown beta-Ga2O3 nanostructures exhibited high purity, wide bandgap, and strong photoluminescence emission, making them promising for applications in optoelectronic devices such as tunable UV-Vis photodetectors.
Article
Physics, Applied
Marika Ohta, Hiroto Tamura, Kazuyuki Uno
Summary: The growth mechanism and process of α-(AlGa)(2)O-3 alloys were investigated using mist chemical vapor deposition, and the contributions of acetylacetonated Al ions and the anchoring mechanism were evaluated.
APPLIED PHYSICS EXPRESS
(2022)
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, Physical
Weiqu Chen, Zimin Chen, Zeqi Li, Zeyuan Fei, Yanli Pei, Gang Wang, Zhiyuan He
Summary: High quality epsilon-phase gallium oxide (Ga2O3) thin films have been successfully grown on silicon substrates using metal-organic chemical vapor deposition (MOCVD). The growth pressure is found to be an important parameter that affects the thin film quality.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Kun Ye, Bochong Wang, Anmin Nie, Kun Zhai, Fusheng Wen, Congpu Mu, Zhisheng Zhao, Jianyong Xiang, Yongjun Tian, Zhongyuan Liu
Summary: The high crystallinity one-dimensional Sb2S3 nanowires were grown on SiO2/Si substrates via CVD technique, showing excellent photodetection properties with a broad photoresponse range and outstanding performance indicators, as well as remarkable switch cycling stability.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Dohwan Jung, Yoonseo Jang, Prakash R. Sultane, Christopher W. Bielawski, Jungwoo Oh
Summary: The energy-band alignment between atomic layer-deposited beryllium oxide (BeO) films and beta-Ga2O3 substrates is reported. It was found that the ALD BeO dielectric on the beta-Ga2O3 substrate provides a higher conduction band offset, which has the potential to lower the gate leakage current density of beta-Ga2O3 power devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Multidisciplinary
Cai Zhang, Xin Jin, Yan Liang, Liu Yang, Jing Li, Rui Wang, Baodan Liu, Xuewei Lv, Xin Jiang
Summary: This study demonstrates the growth of homogeneous and well-aligned [0001]-oriented 1-D GaN nanoarrays through a modified hydride vapor phase epitaxy (HVPE) process. The technique allows for easy control of nanowire density and length, providing Cl-rich growth conditions that result in unique morphology and optical properties of the GaN nanoarrays. The as-synthesized GaN nanoarrays exhibit a hollow bamboo-like structure and show strong visible luminescence, centered at 450 nm with the disappearance of an intrinsic emission peak.
Article
Engineering, Electrical & Electronic
P. R. Jubu, F. K. Yam, O. S. Obaseki, Yushamdan Yusof
Summary: Ga2O3/glass films were successfully synthesized by CVD in the temperature range of 850-1000 degrees Celsius without substrate deformation. Increasing deposition temperature led to higher crystalline quality, thicker films, higher Ga content, and lower O content.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Chunhui Lu, Mingwei Luo, Yanqing Ge, Yuanyuan Huang, Qiyi Zhao, Yixuan Zhou, Xinlong Xu
Summary: Two-dimensional layered materials exhibit layer-dependent optical properties in nonlinear optics due to complex nonlinear absorption processes, which are difficult to understand. Experimental results show that the nonlinear optical properties of chalcogenide compounds are related to both pump intensity and layer number, with saturable absorption occurring in thick samples and reverse saturable absorption occurring in thin samples. The transition between two-photon absorption and saturable absorption is found to be dependent on the layer thickness and band gaps in the materials.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
P. R. Jubu, F. K. Yam, Pannan Kyesmen
Summary: The influence of ZnO layer thickness on Ga2O3/ZnO heterostructured nanocomposites was evaluated, showing that increasing thickness can enhance the concentration of photogenerated electron-hole pairs and improve carrier separation and transportation. This led to an increase in photocurrent density and resulted in different optical and structural properties.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Multidisciplinary
Navpreet Kaur, Dario Zappa, Valentin-Adrian Maraloiu, Elisabetta Comini
Summary: Establishing a platform with different nanostructured oxides is a novel idea for developing highly sensitive and selective sensing devices. The study successfully created 3D-heterostructures consisting of 1D nanowires of NiO and WO3, exhibiting selective behavior towards different gases. The improved sensing performance of the heterostructures is attributed to charge carrier transport through specific interfaces and modulation of charge carriers in the electron depletion layer of WO3 and hole accumulation layer of NiO and NiWO4.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Titao Li, Wei Zheng, Siqi Zhu, Fei Wang, Yanming Zhu, Lemin Jia, Zeguo Lin, Feng Huang
Summary: (AlxGa1-x)(2)O-3 is a promising wide-band-gap sesquioxide for VUV photodetectors and high-power field-effect transistors. This study proposed a high-pressure O-2 (20 atm) annealing strategy to improve the crystallinity of beta-(AlxGa1-x)(2)O-3 and achieve a tunable optical band gap, revealing the local structure of Al3+ and the kinetic mechanism of Al3+ diffusion. The combination of HPOA-treated beta-(Al0.69Ga0.31)(2)O-3 films with p-type graphene led to the fabrication of a VUV photovoltaic detector with improved photovoltage and fast temporal response, providing an important strategy for enhancing the band-gap tunability of sesquioxides and zero-power-consumption photodetectors.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Merve Taner Camci, Matthias Pauly, Christophe Lefevre, Corinne Bouillet, Mounir Maaloum, Gero Decher, David Martel
Summary: This study prepared thin deposits of aligned semiconducting titanium oxide and zinc oxide nanowires using grazing incidence spraying technique on transparent substrates. By measuring the transmittance of linearly polarized light, it was found that titanium oxide nanowires exhibit an orientation-dependent variation of the apparent optical band gap energy at room temperature (>100 meV), providing insights for the design of future optoelectronic devices.
Article
Physics, Applied
Ashutosh Kumar, M. Latzel, S. Christiansen, V. Kumar, R. Singh
APPLIED PHYSICS LETTERS
(2015)
Article
Nanoscience & Nanotechnology
Mamta Khaneja, Santanu Ghosh, P. K. Chaudhury, V. D. Vankar, Vikram Kumar
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2015)
Article
Engineering, Electrical & Electronic
Ashutosh Kumar, S. Nagarajan, M. Sopanen, V. Kumar, R. Singh
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2015)
Article
Nanoscience & Nanotechnology
Ashutosh Kumar, Ranjit Kashid, Arindam Ghosh, Vikram Kumar, Rajendra Singh
ACS APPLIED MATERIALS & INTERFACES
(2016)
Letter
Physics, Applied
Ashutosh Kumar, V. Kumar, R. Singh
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2016)
Article
Nanoscience & Nanotechnology
Mukesh Kumar, Vikram Kumar, R. Singh
NANOSCALE RESEARCH LETTERS
(2017)
Article
Nanoscience & Nanotechnology
Ashutosh Kumar, Raman Kapoor, M. Garg, V. Kumar, R. Singh
Article
Engineering, Electrical & Electronic
Mukesh Kumar, Sudheer Kumar, Neha Chauhan, D. Sakthi Kumar, Vikram Kumar, R. Singh
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2017)
Article
Multidisciplinary Sciences
Ashutosh Kumar, M. Heilmann, Michael Latzel, Raman Kapoor, Intu Sharma, M. Goebelt, Silke H. Christiansen, Vikram Kumar, Rajendra Singh
SCIENTIFIC REPORTS
(2016)
Article
Engineering, Electrical & Electronic
Sahil Soneja, Priyanka Dwivedi, Saakshi Dhanekar, Samaresh Das, Vikram Kumar
IEEE TRANSACTIONS ON NANOTECHNOLOGY
(2018)
Article
Engineering, Electrical & Electronic
Shradha Gupta, J. K. Kaushik, Ankur Gupta, Vikram Kumar, V. R. Balakrishnan
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2020)
Article
Optics
Anshu Goyal, Brajesh S. Yadav, R. Raman, Anand Kumar, Sandeep Dalal, Renu Tyagi, Vikram Kumar, Ashok K. Kapoor
Summary: Radiative defects in various component layers in an AlGaN/GaN HEMT structure were investigated using Cathodoluminescence (CL) spectrum measurements as a function of accelerating voltage. Low electron beam accelerating voltages provided information about defects in the cap layer and the barrier layer, with features such as surface quantum well (SQW) transitions revealing cap layer thickness and quality. The observed changes in CL intensity of the barrier layer were correlated to the formation of aluminium oxide, resulting in higher concentration of deep acceptor defects likely related to adsorbed oxygen on uncapped AlGaN barrier layer samples.
JOURNAL OF LUMINESCENCE
(2021)
Proceedings Paper
Physics, Applied
Mukesh Kumar, Vikram Kumar, R. Singh
DAE SOLID STATE PHYSICS SYMPOSIUM 2015
(2016)
Proceedings Paper
Physics, Applied
Mohd Zubair Ansari, Neeraj Khare, Vikram Kumar
DAE SOLID STATE PHYSICS SYMPOSIUM 2015
(2016)
