Substrate temperature effect on the optical and electrical properties of antimony trisulfide thin films

Thin films of antimony trisulfide Sb2S3 were prepared by thermal vacuum evaporation technique at substrate temperatures from 300-498 K. At substrate temperature T-s less than or equal to 473 K, the films have amorphous structure, while those prepared at T-s = 498 K have polycrystalline structure as identified by X-ray diffraction analysis. The optical investigation of films showed a shift in the optical absorption coefficient (alpha) spectra at the high-energy region. The optical gap increases (1.62 to 1.78 eV) by decreasing the substrate temperature of the deposited films as T-s decreases from 473-300 K. The electrical properties are affected by substrate temperature. The dark electrical resistivity of the films decreases by one order of magnitude as T-s increases from 300 to 498 K. The activation energy decreases with increasing the substrate temperature. (C) 1998 Published by Elsevier Science S.A. All rights reserved.