Some physical investigations on In2S3:Sn sprayed thin film

Abstract

Tin doped In 2 S 3 film was grown by chemical spray pyrolysis method using compressed air as a carrier gas. Structural, morphological, optical and electrical properties of film have been investigated. X-ray diffraction shows well crystallized film according to cubic b-In 2 S 3 phase. The FESEM photograph reveals that the film is dense without pinholes. The average surface roughness and the root-mean square roughness are about 18 and 14 nm, respectively. Optical transmission is more than 60 % in visible region and 85 % in infrared one. Direct band gap energy of 2.62 eV has been found. The impedance plane plot shows semicircle arcs and an electrical equivalent circuit has been proposed to explain the impedance results. We have performed ac and dc conductivity studies inspired from Jonscher and correlated barrier-hopping models. These studies helped establishing significant correlation between temperature and activation energy. From the impedance spectroscopy analysis, we investigated the frequency relaxation phenomenon and the equivalent circuit of such thin film.