Evolution of photoluminescence spectra of stoichiometric CdTe: Dependence on the purity of starting components

A new sublimation method of material purification in a vacuum based on the crystal-vapor-crystal phase transformation is outlined. A basic design of growth reactor and the main parameters of CdTe fine purification are given. With the use of low-temperature photoluminescence (PL), the purification dynamics are revealed. This process is characterized by a complete decomposition of various complexes and by a sharp decrease in the concentration of both shallow-and deep-level residual impurity. At the final stage of purification, a polycrystalline CdTe with stoichiometric composition is obtained, and the impurity-related emission is entirely absent in PL spectra that involve only excitonic lines. The necessity of the fine purification for starting components is experimentally confirmed. Similar results are obtained for ZnTe and ZnSe.

Перевод пока недоступен