Article ID Journal Published Year Pages File Type
743523 Sensors and Actuators B: Chemical 2012 6 Pages PDF
Abstract

Micro humidity sensors are fabricated by radio-frequency sputtering ZnO and In2O3 thin films on SiO2/Si substrates with interdigitated Pt signal electrodes. By adjusting the sensing film form, the micro sensors with a tiny area (1.36 mm × 0.55 mm) exhibit controllable humidity sensing properties. The best sample is obtained by sputtering two times of ZnO and one time of In2O3 on sensor active area (0.63 mm × 0.55 mm). The corresponding impedance changes by more than four orders of magnitude over the whole testing humidity range (from 11% to 95% relative humidity), and the response and recovery times are about 15 s and 40 s, respectively. High stability and good consistency are also observed based on the as-fabricated sensors. The improved and excellent humidity sensing properties are explained by the hetero junctions between ZnO and In2O3 thin films. High sensor performance and large-scale fabricating potentiality demonstrate that the micro humidity sensors are very promising devices for humidity detection which could be produced at industrial level.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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