Study on the Structure, Composition and Optical Properties of Znsxse1-X Thin Films Prepared by Annealing in Sulfur and Selenium Vapor

Abstract

ZnS x Se 1-x thin films were prepared by annealing in sulfur and selenium vapor (ASSV) at 700°C. The properties of the films were studied by XRD, SEM, Raman spectroscopy, UV-VIS transmission spectra, and positron annihilation Doppler broadening spectroscopy (DBS). The results show that all ZnS x Se 1-x thin films have a hexagonal structure, and change gradually from ZnSe to ZnS with increasing x from 0 to 1. And the only formation of ZnS x Se 1-x ternary compound is observed in the films without any detectable impurities. As selenium content increases, the size of the ZnS x Se 1-x crystal grains becomes great with a discontinuous and incompact distribution of the grains on the substrates. The optical absorption edges of ZnS x Se 1-x thin films are found to be redshifted with the decrease of x, with the band-gap energies of 2.53-3.58 eV. Additionally the DBS reveals that ZnS x Se 1-x thin films with 0< x<0.5 have the lower micro-defect content than those with 0.5

Keywords: ZnSxSe1-x thin film, positron annihilation Doppler broadening spectroscopy, magnetron sputtering, vulcanization