Structure and gas sensitivity of the ZnO sensor of ethanol

Abstract

We studied the influence of substrate nature and type of doping on the structure and sensor properties of thin films of ZnO, obtained on the surface of glass, quartz, sital, leuco-sapphire and oxidized silicon by thermo vacuum deposition. With X-ray investigation it shown that the obtained films consist of nanocrystalline zinc oxide, regardless of the nature of the surface, and the best structural perfection characterized ZnO film on the surface of the quartz and glass. The sensitive properties of zinc oxide films to ethanol vapors greatly improved by introducing of doping impurities (Al or In), a highest sensitivity to ethanol was detected for the films of ZnO − Al on the quartz substrate. The proposed sensor can be used to monitor gas environments in the food industry and in the evaluation of alcohol in humans breathing.