The Material of the Sensing Element based on tin Dioxide for the Gas Sensor

Abstract

Using ion-beam sputtering of a composite target in an atmosphere of argon and oxygen, films based on tin dioxide with the addition of yttrium oxide were obtained. It was found that the content of the yttrium additive varies from 0.4 to 6.2 at. %. It was determined that the surface roughness decreases with an increase in the addition of yttrium in films. Using the HRTEM electron microscope, a picture of the microstructure of the Sn—(5 at. %)Y—O film was obtained, on which grains with a size of 5 nm are distinguishable. The roughness data coincide with the data obtained using an electron microscope. The surface resistance of the films increases with an increase in the content of the yttrium additive. The electrophysical parameters of films after their crystallization were determined using the Hall effect. The mobility of charge carriers in the films increases, and the concentration of charge carriers decreases with an increase in the content of the additive. The gas sensitivity of films to ethanol vapors in the air (3000 ppm) was studied for films with a content of 2.8 and 3.6 at. % yttrium. It was found that an increase in the content of yttrium contributes to an increase in the gas sensitivity.