Study On Gas Sensing Optical Properties Of SnO₂ Thin Film Prepared By Sol-gel

SnO2 as a new functional materials, and is widely used in semiconductors, solar cells, gas sensors, liquid crystal displays, catalysts, optical technology surgery and other fields. Gas sensing materials for the preparation of the gas sensor can be used for industrial, defense, civil, and transportation reduction of flammable gas detection。Its market demand is huge. Gas sensitivity of pure SnO2 is lower. To a certain extent, it affectes the gas sensor detection accuracy. Many studies have found that doped with precious metals or other substances that can inhibit the SnO2 Crystal growth, improving the performance of semiconductor materials to improve its gas sensitivity.Based on past studies of magnetron sputtering doped SnO2 thin films, film sensitivity is not high and the reaction time is too long.This paper prepares copper doped and titanium doped SnO2 thin films by the sol-gel. This includes the main experiment: 1, sol-gel process doped SnO2 thin films is studied through experiments on the process conditions explored, such as: doping element, doping concentration, annealing temperature and annealing time, to prepare SnO2 films doped with different copper and titanium doped SnO2 thin films. 2, doped SnO2 films are tested by XRD and tested the thickness.3, study the film's gas-sensing optical property at room temperature.The reflection spectra are tested before and after the reflection of ethanol and other gases. 4, study the return characteristics of sensing films at room temperature, heat and ultraviolet irradiation.This experimental result shows that doped SnO2 thin films prepared by sol-gel performance gas-sensing properties at room temperature. Due to uniformity, thin films have been markedly increased sensitivity and selectivity for different gases. Gas reaction time of titanium doped SnO2 thin film with photocatalytic titanium was shortened.The films can return partly at room temperature. Doped SnO2 thin films have the ability to return in 100℃heating and ultraviolet irradiation. Expected to prepare other doped SnO2 thin films, films in relatively wide range of wavelengths have higher sensitivity to reach the purposes of optical methods of gas detection at room temperature . The films can be used to develope a new generation of gas sensors further.