Properties of Amorphous SnO 2 Thin Films, Prepared by Thermal Evaporation

Abstract

Tin o xide (SnO2) thin films of thickness in the range 100-600 n m are prepared on glass substrates by thermal evaporation at ambient temperatures. The films are characterized by recording their transmittance measurements, X-ray diffraction (XRD) patterns, scanning electron microscope (SEM ) images and energy dispersion X-ray analysis (EDAX). It is found that the films have high t ransmittance and non-sharp absorption edge. XRD d iffractograms showed that the films are amorphous and the SEM micrographs depicted that the surfaces are smooth, uniform and well covered with the material. The EDAX analysis showed that the films are deficient in o xygen. Indirect optical bandgap energy is determined and Urbach tailing in the bandgap is observed and the width of the tail which is related with disorder and localized states is estimated.