Structural and Optical Studies on Sol-Gel Driven Spin-Coated CdS Thin Films

Abstract

Inorganic wide band gap semiconductors are considered as best for optoelectronic devices such as photovoltaic cells, photodetectors, thin film transistors etc. CdS is a more promising semiconductor due to its direct wide band-gap ∼ 2.42 eV and size dependent optical properties. In the present article, structural and optical properties of spin coated CdS thin films are investigated. CdS thin films are annealed at 400 °C for 60 minutes to improve crystalline quality. X-RAY diffraction pattern reveals (002) diffraction plane of wurtzite CdS. The optical properties are analyzed by UV-Visible-NIR spectroscopy. The optical band-gap of CdS thin films varies from 2.25 eV to 2.47 eV which depends on number of deposited layers and the annealing condition.