Amplifying Electron-Donor Signal of the "Water Gate" Enabled Low Detection Ability of a Field-Effect Transistor-Based Humidity Sensor

作     者：Liu, Bohao Chen, Qingqing Hu, Jinyong Zhang, Yong 

作者机构：Xiangtan Univ Sch Phys & Optoelect Xiangtan 411105 Peoples R China Xiangtan Univ Hunan Inst Adv Sensing & Informat Technol Xiangtan 411105 Peoples R China 

出 版 物：《ANALYTICAL CHEMISTRY》 (Anal. Chem.)

年 卷 期：2025年第97卷第5期

页      面：2779-2785页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070302[理学-分析化学] 0703[理学-化学] 

基　　金：National Natural Science Foundation of China [62471425, 62071410, 62101477] National Natural Science Foundation of China [2023RC3133] Science and Technology Innovation Program of Hunan Province 

主　　题：Humidity sensors 

摘      要：Low humidity detection down to the parts per million level is urgently demanded in various industrial applications. The hardly detected tiny electrical signal variations caused by a very small amount of water adsorption are one of the intrinsic reasons that restrain the detection limit of the humidity sensors. Herein, a carbon-based field-effect transistor (FET) humidity sensor utilizing adsorbed water as the dual function of a sensing gate and analyte was proposed. Owing to the electron donor property of the water gate that can serve as a negative voltage exerted on the dielectric layer, the electrical conductivity of the FET s channel can be significantly modulated, therefore realizing signal amplification. The proposed sensor presents a detection limit of lower than 1% RH. Besides, the fabricated sensors show good batch consistency (response deviation of 0.5%), repeatability, long-term stability, and acceptable hysteresis (6.3% relative humidity (RH)) in humidity detection. We hope that our work can offer a novel strategy for the application and integration of low humidity detection from the device aspect rather than sensing materials synthesis.