Microstructure, electrical and optical properties of Cd-doped CdTe thin films deposited by close-spaced-sublimation

Abstract

Cd-doped CdTe polycrystalline films were deposited on ITO/glass substrates by close-spaced-sublimation (CSS)method. The microstructural, morphological, electrical and optical properties of the films were characterized by X-ray diffraction, scanning electron microscopy, Hall effect, and optical absorption. It is found that the crystallinity is improved, the electrical resistivity drops 4—5 orders of magnitude and the conductivity changes from p-type to n-type when pure CdTe film is doped with a proper amount of Cd. There is no obvious influence on the optical band gaps of the films by the doping of Cd.