Development of a rGO-BiVO4 Heterojunction Humidity Sensor with Boosted Performance

• Published in: ACS applied materials & interfaces 2021-06, Vol.13 (23), p.27188-27199
• Main Authors: Wu, Zhilin, Sun, Xia, Guo, Xuezheng, Ding, Yanqiao, Ou, Yi, Yang, Han, Chen, Yanhong, Hu, Yanting, Kuang, Deilin, Zhao, Chengjiu, He, Yong
• Format: Article
• Language: English
• Subjects: Functional Inorganic Materials and Devices
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.1c05753

Humidity sensors with good repeatability, low hysteresis, and low-power consumption are increasingly important for environmental monitoring and industrial control applications. Herein, an impedance-type humidity sensor under low working voltage (5 mV) utilizing a rGO-BiVO4 nanocomposite is demonstrated. The rGO-BiVO4 humidity sensor exhibits superior sensing performances, including good repeatability, negligible hysteresis (0.47%), fast response and recovery time, low power consumption, good stability, and anti-interference ability. The ultraviolet–visible absorption spectrum reveals that the narrow band gap of the rGO-BiVO4 nanocomposite is conductive to the electron transfer. The complex impedance spectra and the energy band structure analysis further suggest that the boosted humidity performance results from the formation of a heterojunction and the decrease of the heterojunction barrier height. The facile fabrication route, enhanced sensing performance, and excellent device reliability make the rGO-BiVO4 sensor highly attractive for high-end humidity sensing applications.