Optical and photoelectrical properties of β-In2S3 thin films prepared by two-stage process

β-In2S3 films were grown on glass as well as on quartz substrates by rapid heating of metallic indium films in H2S atmosphere. The effect of sulfurization temperature and time on the growth, structural, electrical and photoelectrical properties of β-In2S3 films has been investigated. Highly oriented single-phase β-In2S3 films were grown by the sulfurization technique. The morphology and composition of films have been characterized. The optical band gap of β-In2S3 is found to vary from 1.9 to 2.5 eV when the sulfurization temperature is varied from 300 to 600 °C or by increasing the sulfurization time. The electrical properties of the thin films have also been studied; they have n-type electrical conductivity. The photoelectrical properties of the β-In2S3 films are also found to depend on the sulfurizing temperature. A high photoresponse is obtained for films prepared at a sulfurizing temperature of 600 °C. β-In2S3 can be used as an alternative to toxic CdS as a window layer in photovoltaic technology.