Abstract
Tin-doped indium sulfide (In2S3:Sn) thin films were deposited on the glass substrate by varying molar ratio of Sn:In from 0 to 4% using spray pyrolysis. X-ray diffraction analysis showed that the deposited films were polycrystalline and crystallized in a cubic structure. The evaluated crystallite size varied in the range, 14.8-25.5 nm. The root-mean-square (RMS) roughness values decreased from 39 to 17 nm. Raman studies showed different peaks related to In2S3 phase and no additional phase was detected. The optical analysis allowed us to know that In2S3:Sn thin films had a transparency over 65%-70% in the visible region and 75%-90% in the near-infrared region. It displayed a band gap from 2.68 to 2.91 eV for the direct transition. The refractive index (n) values of In2S3:Sn thin films decreased from 2.45 to 2.37. The extinction coefficient (k) values were in the range of 0.01-0.21. Effect of tin doping on ethanol sensing response was also investigated. A slight enhancement in response is shown for In2S3:1%Sn sample.