Dependence of Structural and Optoelectrical Properties on the Composition of Electron Beam Evaporated Zn_xCd_(1-x)S Thin Films

摘要

Thin films of Zn_xCd_(1-x)S have been prepared by electron beam evaporation of a mixture of ZnS & CdS powders. The films are deposited onto sodalime glass slides under similar conditions. The composition of the films is varied from CdS to ZnS (x = 0 to 1). The films show a regular change in color from toner red to orange yellow as Zn concentration increases to maximum. These films are characterized for their optical, electrical and structural properties. The bandgap value of Zn_xCd_(1-x)S films is found to vary linearly from 2.20 eV to 3.44 eV with change in the x value from 0 to 1. The resistivity of these films is in the range of 171.0 Ωcm to 5.5 x 10~6 Ωcm for x = 0～0.6. All the samples show cubic structure after annealing in air at 250℃ for 40 min. The lattice constant α_o varies from 0.5884 nm to 0.54109 nm linearly.