Effect of F doping on the properties of zinc tin oxide thin films for UV photodetector applications prepared by low-cost nebulizer spray pyrolysis method

Abstract

The fluorine doped zinc tin oxide (FZTO) thin films were fabricated using nebulizer spray pyrolysis method and fluorine doping effect on structural, morphological, optical and photo sensing properties were investigated. The XRD results show that all the prepared films are polycrystalline in nature and exhibit a hexagonal structure with c-axis growth orientation. The SEM images of all the films displays uniform surface without any crack and well packed with defined granules. The EDX spectra establishes that the existence of Zn, Sn O, and F components in the fabricated films with their nominal stoichiometric percentage. The water contact angle assessment indicates the reduction of surface roughness. The UV–Visible transmittance spectra of the films exhibit >75% and the blue shift of energy band gap is indicating the increase of free carriers. The PL emission spectra show that the presence of neutral and singly ionized oxygen vacancies (V0° &V0+) and these defects acting as carrier trap. The prepared films exhibit a good response to UV light and enhance the photo current up to 597 μA and the recorded raise and decay time are 3.29 and 4.17s respectively.