Investigation of the Effect of ZnO Film Thickness Over the Gas Sensor Developed for Sensing Carbon Monoxide

In this work, a facile and inexpensive ZnO thin film‐based Carbon monoxide gas sensor has been fabricated using a solution‐process technique. To vary the thickness of ZnO thin films, the precursor solutions of two different molarities, 3M and 5M have been spin‐coated over glass substrates. The 3M ZnO thin film device has demonstrated more than two times improvement in sensing response as compared to 5M ZnO films, for 50 ppm Carbon monoxide concentration. Additionally, The 3M ZnO film was found to perform better for low Carbon monoxide concentrations, whereas the 5M ZnO film showed a linear response over a wider range of Carbon monoxide concentrations. The gas sensing mechanism and the impact of film thickness on the performance of the device have been thoroughly studied and discussed, which may open the doors for the design and development of facile and high‐sensitivity metal oxide‐based gas sensors.This article is protected by copyright. All rights reserved.