Effect of heat treatment in sulfur on structural, optical and electrical properties of thermally evaporated In2S3 thin films

Crystallinity, optical band gap, resistivity and photoresponse of thermally evaporated In2S3 thin films deposited at a temperature 350 °C further annealed in sulfur vapour different range 200–300 is investigated. It observed that with an increase annealing temperature, predominantly β-In2S3 phase formed the gap for indirect allowed transitions increases from 1.6 eV to 2.0 direct 2.3 2.7 eV. The electrophysical properties indicate activation mechanism conductivity energy 0.5–0.73 eV, which typical presence indium vacancies crystal structure replacement by oxygen atoms. also noted temperatures 250–300 leads photosensitivity films, suitable photovoltaic applications.