Optical and structural properties of ZnS_xSe_1−x thin films deposited by thermal evaporation

¹ Optics Laboratories, P.O. Box 1021, Islamabad, Pakistan
² Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad, Pakistan
³ Physics Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad, Pakistan

Corresponding author: qayyum@pinstech.org.pk

Received: 9 February 2009
Accepted: 24 April 2009
Published online: 4 July 2009

Abstract

The ZnS_xSe (0 ≤ x ≤ 1) films were deposited on soda lime glass substrates by thermal evaporation technique. Optical and structural properties of these films were compared with the ZnS_xSe films deposited by various other techniques. XRD measurement showed that ZnS_xSe films are polycrystalline in nature with the preferred orientation along [111]. It was observed that the lattice constant decreases and the optical energy band gap increases with the sulfur content of the film. These results are in good agreement with the properties of ZnS_xSe films deposited by various other methods. Additionally, it was observed that the refractive index of a ZnS_xSe film decreases with increasing sulfur content. The results reported in this paper suggest that the lattice constants, optical energy band gap and refractive index of ZnS_xSe film can be tailored for a specific application by selecting suitable value of x.