Optical Properties of Al- and Sb-Doped CdTe Thin Films

Abstract

Nondoped and (Al, Sb)-doped CdTe thin films with 0.5, 1.5, and 2.5  wt.%, respectively, were deposited by thermal evaporation technique under vacuum onto Corning 7059 glass at substrate temperatures () of room temperature (RT) and 423 K. The optical properties of deposited CdTe films such as band gap, refractive index (n), extinction coefficient (), and dielectric coefficients were investigated as function of Al and Sb wt.% doping, respectively. The results showed that films have direct optical transition. Increasing and the wt.% of both types of dopant, the band gap decrease but the optical is constant asn, and real and imaginary parts of the dielectric coefficient increase.