Fabrication and Application of Thin Film Semiconductor Sensors for the Detection of Volatile Organic Compounds

摘要

Volatile Organic Compounds (VOCs) are highly reactive, often mixed with interfering gases and more importantly, their vapours in the gaseous form respond to the gas sensor devices. Oxide semiconductor based thin film gas sensors play vital role in detecting, monitoring and controlling the presence of hazardous and harmful gases in the environment at very low concentration and hence are tested for the detection of harmful or industrially important VOCs. The demand of sensitive as well stable gas/vapour sensors for direct sensing application has increased the importance of In_2O_3: SnO_2 based semiconductor materials. The paper presents the fabrication aspects of thin film gas sensors based on x1In_2O_3: x2SnO_2 compound and also their application for the detection of some important volatile organic compounds. Thin films of x1In_2O_3: x2SnO_2 were deposited using Thermal Evaporation technique and under the optimized fabrication conditions, the vapour sensors were prepared and mounted on the proper contact jig. Their response to the presence of Volatile Organic Compounds like CCl_4 was examined. The stability, the sensitivity and the response time of the sensors were studied for the different concentrations of test vapours.