%A Zeng Liu(刘增), Ling Du(都灵), Shao-Hui Zhang(张少辉), Ang Bian(边昂), Jun-Peng Fang(方君鹏), Chen-Yang Xing(邢晨阳), Shan Li(李山), Jin-Cheng Tang(汤谨诚), Yu-Feng Guo(郭宇锋), and Wei-Hua Tang(唐为华) %T Achieving highly-efficient H2S gas sensor by flower-like SnO2-SnO/porous GaN heterojunction %0 Journal Article %D 2023 %J Chin. Phys. B %R 10.1088/1674-1056/ac6947 %P 20701-020701 %V 32 %N 2 %U {https://cpb.iphy.ac.cn/CN/abstract/article_125442.shtml} %8 2023-01-10 %X A flower-like SnO2-SnO/porous GaN (FSS/PGaN) heterojunction was fabricated for the first time via a facile spraying process, and the whole process also involved hydrothermal preparation of FSS and electrochemical wet etching of GaN, and SnO2-SnO composites with p-n junctions were loaded onto PGaN surface directly applied to H2S sensor. Meanwhile, the excellent transport capability of heterojunction between FSS and PGaN facilitates electron transfer, that is, a response time as short as 65 s and a release time up to 27 s can be achieved merely at 150 ℃ under 50 ppm H2S concentration, which has laid a reasonable theoretical and experimental foundation for the subsequent PGaN-based heterojunction gas sensor. The lowering working temperature and high sensitivity (23.5 at 200 ppm H2S) are attributed to the structure of PGaN itself and the heterojunction between SnO2-SnO and PGaN. In addition, the as-obtained sensor showed ultra-high test stability. The simple design strategy of FSS/PGaN-based H2S sensor highlights its potential in various applications.