High sensing response of β-Ga2O3 thin film towards ammonia vapours: Influencing factors at room temperature

The gallium oxide (beta-Ga2O3) thin films were deposited onto a quartz substrate using spray pyrolysis technique with gallium acetylacetonate as precursor salt. The X-ray diffraction pattern of the annealed film at 900 degrees C indicated the formation of monoclinic beta-Ga2O3 phase with polycrystalline nature. Field emission scanning electron micrograph showed nanocrystallites over the film surface. The ammonia sensing property of the film at room temperature (similar to 30 degrees C) was studied by chemiresistive method. Influencing factors such as vapour concentration, relative humidity and film thickness in ammonia sensing performance were studied and reported. (C) 2014 Elsevier B.V. All rights reserved.