A highly transparent humidity sensor with fast response speed based on α-MoO3 thin films

Hailong Ma; Huajing Fang; Wenting Wu; Cheng Zheng; Liangliang Wu; Hong Wang

doi:10.1039/D0RA03958F

A highly transparent humidity sensor with fast response speed based on α-MoO₃ thin films†

Hailong Ma,^a Huajing Fang,

*^a Wenting Wu,^a Cheng Zheng,^b Liangliang Wu^b and Hong Wang

*^c

Author affiliations

* Corresponding authors

^a State Key Laboratory for Mechanical Behavior of Materials, School of Material Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
E-mail: fanghj@xjtu.edu.cn

^b School of Electronic and Information Engineering, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China

^c Department of Materials Science and Engineering, Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices, Southern University of Science and Technology, Shenzhen 518055, China
E-mail: wangh6@sustech.edu.cn

Abstract

Metal oxide based humidity sensors are important indicators in environmental monitoring. However, most of them are non-transparent and have a long response time, which cannot meet the application of real-time humidity sensing in transparent electronics. Here, we report a metal oxide humidity sensor based on chemically synthesized molybdenum oxide (α-MoO₃) thin films. By a green reaction in an ice water bath, the stable precursor containing nanocrystalline colloids was obtained. Molybdenum oxide films with controllable morphology were fabricated through one-step spin coating. The α-MoO₃ based humidity sensor exhibits extremely high transparency (85%) in the visible region and has short response and recovery times (0.97 and 12.11 s). In addition, it also shows high sensitivity, good logarithmic linearity and selectivity in a wide relative humidity range of 11% to 95%. The mechanism of humidity sensing was further studied by complex impedance spectroscopy. This novel metal oxide humidity sensor combined with high transparency and fast response speed is expected to broaden the application ranges of humidity sensors.

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Article information

DOI: https://doi.org/10.1039/D0RA03958F
Article type: Paper
Submitted: 02 May 2020
Accepted: 29 Jun 2020
First published: 06 Jul 2020
This article is Open Access

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RSC Adv., 2020,10, 25467-25474

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A highly transparent humidity sensor with fast response speed based on α-MoO₃ thin films

H. Ma, H. Fang, W. Wu, C. Zheng, L. Wu and H. Wang, RSC Adv., 2020, 10, 25467 DOI: 10.1039/D0RA03958F

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