Robust Deep UV Photodetectors Based on One‐Step‐Grown Polycrystalline Ga<sub>2</sub>O<sub>3</sub> Film via Pulsed Laser Deposition toward Extreme‐Environment Application
Hong Huang, Haoran Yin, Keju Han, Yilin Wang, Zhiwei Wang, Xiao Feng, Yanni Zou, Xuanze Zhou, Guangwei Xu, Xiaohu Hou, Xiaolong Zhao, Shibing Long
Abstract
Abstract Gallium oxide (Ga 2 O 3 ), with an ultrawide bandgap corresponding to the deep ultraviolet (DUV) range, has attracted significant attention in optical filter‐free photodetectors. In practical terms, DUV photodetectors employed in extreme conditions, for example, flame detection and space exploration, face the challenges of performance degradation caused by high/low‐temperature transformation. Here, DUV photodetectors are tailored with high durability and stability by one‐step‐grown β‐Ga 2 O 3 films via pulsed laser deposition. A high‐oxygen‐pressure scheme effectively addresses the issue of film‐free deposition at specifically high temperatures, facilitating the formation of polycrystalline high‐resistivity β‐Ga 2 O 3 films. As a result, the devices exhibit outstanding performance, including a low dark current (4.4 pA @30 V), high photoresponsivity (147.36 A W −1 ), and fast response time (3.1/22.6 ms). Additionally, the photoresponse performance shows minimal degradation at high temperatures up to 300 °C and even improves at low temperatures down to −100 °C, ranking it among the most robust DUV photodetectors. The mechanism of photoresponse, involving the exciton formation, bandgap evolution, carrier‐phonon scatter, etc., is also elucidated in a wide temperature range. This work provides an efficient solution for developing robust Ga 2 O 3 DUV photodetectors with excellent performance for extreme‐condition applications.