Annealing-induced Changes in the Electronic and Structural Properties of ZnTe Substrates

The aim of this study is to demonstrate that the electronic and structural properties of II–VI substrates, here ZnTe, can be dramatically affected by thermal heating at temperatures in the range of those typically used in the epitaxial metalorganic chemical vapor deposition processes. Photoluminescence response shows that annealing at these temperatures produces a reduction of the sample crystalline quality, decreasing the free exciton emission relative to the deep level related one. Some factors, like the change in the charge and stress state of dislocations, Cu diffusion, and oxygen incorporation, could be responsible for changes in the substrate properties, which can produce stresses and contamination in the deposited sample.