Physical, optical and sensing properties of sprayed zinc doped tin oxide films

Abstract

Zn doped SnO2 films have been prepared on Si (100) and glass substrates by ultrasonic spray pyrolysis deposition technique from tin chloride dehydrate doped with different Zn acetate concentration. EDX techniques employed to investigate the elements contents. Zn element in the prepared films increased from 0 to about ∼5 at.% as the Zn acetate solution concentration increased from 0 to 20%. XRD pattern showed four orientations (110), (101), (200) and (211). Average grain size decreased with Zn concentration, and texture factor (TC) evaluated from intensity of the diffraction peaks. Raman spectrua correlate with XRD results. Thickness and morphology of the films explored from cross section and surface SEM images, respectively. 2D AFM images clarify the modifications of the morphology with adding Zn acetate. The values of roughness (Ra and RMS) are decreased with Zn concentrations. The band gap (Eg) and transparency of the films have been deduced from UV spectra, where Eg declined with Zn concentration. Acetone, ethanol, methanol, humidity (H2O) and NH3 vapor gases confirmed the sensing properties at room temperature of the deposited films. SnO2 films doped with Zn are exhibited enhanced response in humidity and ethanol vapors at room temperature.