Article
Materials Science, Multidisciplinary
Ray-Hua Horng, Apoorva Sood, Siddharth Rana, Niall Tumity, Fu-Gow Tarntair, Catherine Langpoklakpam, Hao-Chung Kuo, Jitendra Pratap Singh
Summary: Conductive β-Ga2O3 epilayers grown on the sapphire substrate using MOCVD were studied by Si-ion implanted. A metal-insulator-semiconductor diode (MISD) was fabricated using undoped and Si-implanted β-Ga2O3 epitaxial layer. The electrical and carrier transport properties of different MISD with different distance between cathode and anode contact were investigated.
MATERIALS TODAY ADVANCES
(2023)
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
Anushka Bansal, Nadire Nayir, Ke Wang, Patrick Rondomanski, Shruti Subramanian, Shalini Kumari, Joshua A. Robinson, Adri C. T. van Duin, Joan M. Redwing
Summary: Ultrathin 2D-GaNx can be formed by Ga intercalation into epitaxial graphene followed by nitridation. The influence of graphene layer thickness and chemical functionalization on Ga intercalation and 2D-GaNx formation is examined using experimental and theoretical studies.
Article
Nanoscience & Nanotechnology
A. F. M. Anhar Uddin Bhuiyan, Zixuan Feng, Hsien-Lien Huang, Lingyu Meng, Jinwoo Hwang, Hongping Zhao
Summary: Single alpha-phase (AlxGa1-x)(2)O-3 thin films were successfully grown on m-plane sapphire substrates via metalorganic chemical vapor deposition, demonstrating high quality and uniformity. The influence of growth parameters on film properties was further investigated. X-ray photoelectron spectroscopy was employed to characterize the aluminum content and bandgaps, with the band alignment at heterojunctions also studied.
Article
Chemistry, Physical
Nico Lovergine, Ilio Miccoli, Leander Tapfer, Paola Prete
Summary: The lattice tilt, mosaicity, and defect content of relaxed GaAs grown on exactly-oriented and 4 degrees-offcut (11 1)Si were investigated. Thin GaAs single-layers grown at 400°C and annealed at 700°C showed a density of surface pinholes. Double-layer samples were obtained by GaAs overgrowth at 700°C. The GaAs epilayers were tilted with respect to Si and rotational twins were observed in X-ray diffraction (XRD) pole figures.
APPLIED SURFACE SCIENCE
(2023)
Article
Crystallography
Ta-Shun Chou, Saud Bin Anooz, Raimund Grueneberg, Natasha Dropka, Wolfram Miller, Thi Thuy Vi Tran, Jana Rehm, Martin Albrecht, Andreas Popp
Summary: This study demonstrates the use of Random Forest, a machine learning approach, for predicting the growth rate of beta-Ga2O3 in metal-organic vapor phase epitaxy (MOVPE) by analyzing its growth process on sapphire. The proposed model can effectively evaluate the complex non-linear dependencies among growth parameters and optimize them to achieve the optimal growth rate. It achieves a high predictive power with a coefficient of determination (R-2) of 0.95 and 0.92 for the training and testing sets, respectively. The model's outcome is applicable to both homoepitaxial and heteroepitaxial processes, as well as different substrate orientations.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Chemistry, Multidisciplinary
Ransheng Chen, Qiang Li, Qifan Zhang, Jiaxing Li, Zhihao Zhang, Wannian Fang, Lingyan Wang, Feng Yun, Tao Wang, Yue Hao
Summary: A high-crystallinity hBN film has been successfully achieved on a catalyst-free sapphire substrate using the LPCVD technique. The nitridation process is found to play a crucial role in obtaining high-quality hBN with suppressive N-vacancy. The growth mechanism of hBN on sapphire has been proposed, and the morphology of hBN evolves with increasing growth pressure.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Crystallography
Narihito Okada, Takahiro Saito, Sachie Fujikawa, Noritoshi Maeda, Masafumi Jo, Hideki Hirayama, Kazuyuki Tadatomo
Summary: Epitaxial lateral overgrowth (ELO) of AlN was performed by varying a vicinal off-cut angle of sapphire substrates, resulting in reduced dislocations and decreased EPD with increasing thickness.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Chemistry, Multidisciplinary
Hua-Chiang Wen, Ssu-Kuan Wu, Cheng-Wei Liu, Jin-Ji Dai, Wu-Ching Chou
Summary: The nanotribological properties of AlxGa1-xN epitaxial films grown on low-temperature-grown GaN/AlN/Si substrates were investigated. It was found that the Al compositions played a crucial role in determining the strength of bonding forces and shear resistance. The measured friction coefficient (mu) values decreased with increasing Al compositions, indicating a transition from brittleness to ductility in the AlxGa1-xN system.
Article
Materials Science, Multidisciplinary
Xiucheng Wei, Pinku Roy, Zihao Yang, Di Zhang, Zihao He, Ping Lu, Olivia Licata, Haiyan Wang, Baishakhi Mazumder, Nag Patibandla, Yong Cao, Hao Zeng, Mingwei Zhu, Quanxi Jia
Summary: This study achieved high-quality ultrathin epitaxial NbN films using PVD technology at low temperatures, opening up new possibilities for quantum devices. The research revealed a close correlation between film thickness and superconducting properties, with lattice strain observed in films below 20 nm.
MATERIALS RESEARCH LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Zhiqiang Liu, Bingyao Liu, Fang Ren, Yue Yin, Shuo Zhang, Meng Liang, Zhipeng Dou, Zhetong Liu, Shenyuan Yang, Jianchang Yan, Tongbo Wei, Xiaoyan Yi, Chaoxing Wu, Tailiang Guo, Junxi Wang, Yong Zhang, Jinmin Li, Peng Gao
Summary: This study investigates the polarity determination and evolution mechanism of polar wurtzite nitrides on nonpolar substrates. The findings reveal a spontaneous polarity inversion during the growth and the formation of inherent inverse grain boundaries. Additionally, it identifies the occurrence of vertical two-dimensional electron accumulation originating from the lattice symmetry breaking at the inverse grain boundary.
Article
Chemistry, Physical
M. Nistor, E. Millon, C. Cachoncinlle, C. Ghica, C. Hebert, J. Perriere
Summary: Nd-doped ZnO thin films were deposited using PED under oblique conditions, resulting in smooth, compact films with inclined columnar grains. The films exhibit a unique wurtzite phase with a specific epitaxial relationship with the sapphire substrate.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Yu-Hsuan Hsu, Wan-Yu Wu, Kun-Lin Lin, Yu-Hsuan Chen, Yi-Hsin Lin, Po-Liang Liu, Ching-Lien Hsiao, Ray-Hua Horng
Summary: In this study, epsilon-Ga2O3 epilayers are grown on c-plane sapphire by metal-organic chemical vapor deposition, and the structural relationship between epsilon-Ga2O3 and kappa-Ga2O3 is elucidated through detailed transmission electron microscopy characterization.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Takahiro Kato, Hiroyuki Nishinaka, Kazuki Shimazoe, Masahiro Yoshimoto
Summary: Epitaxial delta-Ga2O3 thin films were successfully grown on various planes of YSZ and c-plane sapphire substrates by inserting beta-Fe2O3 and bcc-In2O3 buffer layers. The growth involved reducing lattice mismatch and exploring the thermal stability of the buffer layers. Furthermore, the growth of both alpha- and delta-Ga2O3 thin films on c-plane sapphire was achieved using specific buffer layers.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Valerie Demange, Xavier Portier, Sophie Ollivier, Mathieu Pasturel, Thierry Roisnel, Maryline Guilloux-Viry, Christian Hebert, Magdalena Nistor, Christophe Cachoncinlle, Eric Millon, Jacques Perriere
Summary: The room temperature growth of zinc-doped iron oxide films (Zn:FeOx) on different sapphire substrates was investigated using the pulsed-laser deposition method. Characterization techniques including Rutherford backscattering spectrometry, X-ray diffraction analysis, pole figure measurements, and transmission electron microscopy were employed to determine the nature of the oxide phases, their texture, and the in-plane epitaxial relationships. The results showed variations in oxide phases and textures on different sapphire substrates.
CRYSTAL GROWTH & DESIGN
(2023)
