Electron structure effects of S-doped In2O3 flowers on NO2 sensitivity

To further develop sensing materials for NO2 gas detection practical application, the operating temperature of the sensor should be significantly reduced. In this paper, In2O3 flowers were prepared by the microwave-assisted hydrothermal method. Then, In2O3 was doped using TAA (thioacetamide). The prepared S-doped In2O3 flowers have good gas sensitivity and significantly reduced operating temperature. When exposed to 10 ppm NO2 gas, the corresponding response was 250 at 118 °C. It can be demonstrated by the first principle calculations, in which the doping of S atoms changes the electron structure of In2O3 from semiconductor to metal with a lower potential barrier. Then, significantly affects the electron crossing the intergranular potential barriers. Therefore, the operating temperature of the sensor can be reduced. Our research results will provide new research ideas and technical approaches for designing, fabricating, and applying a new generation of In2O3 gas sensors.