Abstract
Transparent In2O3 film has been synthesized by one-step thermal evaporation for CH4 gas sensor. X-ray diffraction pattern confirmed the polycrystalline cubic bixbyite-type structure of indium oxide film. The transmittance of the film was recorded of 71%, where the optical band gap was found to be 3.68 eV. A gas sensor was fabricated by In2O3 film, and the sensor was calcined at 350 degrees C before the gas sensing investigation. The gas sensing performance of the film toward CH4 gas was measured at various operating temperatures. At low temperature the sensor exhibited a good performance, while at high temperature of 250 and 350 degrees C the sensor exhibited an undesirable behavior. Afterward, the sensor undergoes thermal treatment at 450 degrees C once again before the applying for the sensing measurement. It was observed that the gas sensing performance was dramatically improved, showing a good repeatability and stability.