CO2 gas sensing properties of La2O3 thin films deposited at various substrate temperatures

Abstract

Carbon dioxide gas (CO2) sensing properties of La2O3 thin films synthesized by spray pyrolysis method are reported. La2O3 thin films deposited at different substrate temperatures (573–623 K) are characterized for their structural, surface morphology, optical and electrical properties and used for CO2 gas response measurements. SEM analyses indicate porous surface morphology. The deposited La2O3 films are crystalline with pronounced orientation along (110) plane, uniform and adhere to the glass substrate. From optical absorbance studies, the optical band gap is found to be 4.2 eV. With porous surface morphology, the maximum response of 18% at 623 K substrate temperature is recorded on exposure of 350 ppm of CO2 gas.