Stable and Fast-Response Capacitive Humidity Sensors Based on a ZnO Nanopowder/PVP-RGO Multilayer

Hui Yang; Qiangqiang Ye; Ruixue Zeng; Junkai Zhang; Lei Yue; Ming Xu; Zhi-Jun Qiu; Dongping Wu

doi:10.3390/s17102415

Stable and Fast-Response Capacitive Humidity Sensors Based on a ZnO Nanopowder/PVP-RGO Multilayer

Sensors (Basel). 2017 Oct 23;17(10):2415. doi: 10.3390/s17102415.

Authors

Hui Yang¹, Qiangqiang Ye², Ruixue Zeng³, Junkai Zhang⁴, Lei Yue⁵, Ming Xu⁶, Zhi-Jun Qiu^{7

8}, Dongping Wu⁹

Affiliations

¹ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 15110720073@fudan.edu.cn.
² State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 14210720116@fudan.edu.cn.
³ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 13110720024@fudan.edu.cn.
⁴ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 15110720077@fudan.edu.cn.
⁵ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 14110720067@fudan.edu.cn.
⁶ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. xuming123@263.net.
⁷ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. zjqiu@fudan.edu.cn.
⁸ School of Information Science and Technology, Fudan University, Shanghai 200433, China. zjqiu@fudan.edu.cn.
⁹ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. dongpingwu@fudan.edu.cn.

Abstract

In this paper, capacitive-type humidity sensors were prepared by sequentially drop-coating the aqueous suspensions of zinc oxide (ZnO) nanopowders and polyvinyl pyrrolidone-reduced graphene oxide (PVP-RGO) nanocomposites onto interdigitated electrodes. Significant improvements in both sensitivity and linearity were achieved for the ZnO/PVP-RGO sensors compared with the PVP-RGO/ZnO, PVP-RGO, and ZnO counterparts. Moreover, the produced ZnO/PVP-RGO sensors exhibited rather small hysteresis, fast response-recovery time, and long-term stability. Based on morphological and structural analyses, it can be inferred that the excellent humidity sensing properties of the ZnO/PVP-RGO sensors may be attributed to the high surface-to-volume ratio of the multilayer structure and the supporting roles of the PVP-RGO nanocomposites. The results in this work hence provide adequate guidelines for designing high-performance humidity sensors that make use of the multilayer structure of semiconductor oxide materials and PVP-RGO nanocomposites.

Keywords: PVP; RGO; ZnO nanopowders; capacitive humidity sensor.