The epitaxial growth and optical properties of ZnS thin films, deposited by pulsed laser deposition

Zinc sulfide (ZnS) thin films have been epitaxially grown on c-Al2O3 (0 0 0 l) substrates by pulsed laser deposition. The deposition temperature was varied in the range of 450-725 0C at the fixed oxygen pressure of 10-5 Torr. The crystallinity was examined by two-dimensional x-ray diffraction. The full-width at half-maximum of diffraction peaks decreased with an increase in growth temperature. ZnS films exhibit sharp transmittance edges around 330 nm when measured at room temperature. The energy band gaps at different temperatures were obtained by transmittance spectroscopy measurement, which slightly increases from 3.74 to 3.76 eV with an increase in deposition temperature.