Characterization of vacuum-evaporated ZnSe thin films

Abstract

ZnSe thin films were deposited onto glass substrates under a vacuum of 3×10 −5 Torr by using vacuum evaporation technique. Rutherford backscattering spectrometry technique is used to measure the composition and thickness of the deposited films. The composition of the deposited films is found to be nearly stoichiometric. The X-ray diffractogram reveals a preferential orientation along (1 1 1) direction, and the structural parameters such as crystallite size, dislocation density, strain and lattice parameters are calculated, and also the effect of film thickness and substrate temperature of the deposited films was also discussed. It is observed that the crystallite size increases from 20.11 to 55.56 nm with the increase in film thickness. The X-ray diffraction (XRD) studies show that the structure of the deposited films is cubic. The crystalline nature of the deposited films is also confirmed by Raman scattering measurements. In the optical studies, optical band-gap values decrease with the increase in film thickness and substrate temperatures. In the DC conduction studies, the conduction mechanism is found to be exponential trap distribution and the results are discussed.