Study of the structural and photoluminescence properties of CdTe polycrystalline films deposited by close-spaced vacuum sublimation

摘要

The polycrystalline CdTe films were deposited by the close-spaced vacuum evaporation at the different substrate temperatures (150-550 ℃). The X-ray diffraction measurements of structural and substructural properties of these films were carried out to study their phase composition and texture. The films' parameters such as the coherent scattering domain size, microdeformation level and mean density of dislocations were determined based on the broadening of diffraction peaks. In this case the Hall and three-fold convolution approximations were used. Surface morphology, grain size and growth mechanism of the films were determined by the scanning electron microscopy. The low temperature photoluminescence measurements allowed us to establish the correlation between the point and extended defect structure on the one hand and the growth conditions on the other. As a result, the growth conditions of CdTe polycrystalline films with fairly good crystal and optical quality were determined.