Size-Dependent Phase Transition in Ultrathin Ga<sub>2</sub>O<sub>3</sub> Nanowires
Jiaheng Wang, Jiaheng Wang, Xiaoxi Guan, Zheng He, Ligong Zhao, Renhui Jiang, Peili Zhao, Ying Zhang, Jie Hu, Pei Li, Shuangfeng Jia, Jianbo Wang, Jianbo Wang
Abstract
Gallium oxide (Ga 2 O 3 ) has attracted extensive attention as a potential candidate for low-dimensional metal-oxide-semiconductor field-effect transistors (MOSFETs) due to its wide bandgap, controllable doping, and low cost. The structural stability of nanoscale Ga 2 O 3 is the key parameter for designing and constructing a MOSFET, which however remains unexplored. Using in situ transmission electron microscopy, we reveal the size-dependent phase transition of sub-2 nm Ga 2 O 3 nanowires. Based on theoretical calculations, the transformation pathways from the initial monoclinic β-phase to an intermediate cubic γ-phase and then back to the β-phase have been mapped and identified as a sequence of Ga cation migrations. Our results provide fundamental insights into the Ga 2 O 3 phase stability within the nanoscale, which is crucial for advancing the miniaturization, light weight, and integration of wide-bandgap semiconductor devices.