Point defects and diffusion in cadmium telluride

Point defect thermodynamics at the solid–vapor equilibrium and point defect diffusion is reviewed in cadmium telluride with an emphasis on recent experimental findings. Principles and benefit of respective experimental methods studying defect structure both in situ in high-temperature thermodynamic equilibrium and frozen at room or lower temperatures are outlined. The comprehensive theory based on quasichemical formalism is presented in a form, which can be easily applied to binary semiconductors. The effect of Fermi level to the point defect concentration and diffusion is demonstrated at length. We argue that in spite of increasing knowledge the understanding of defect structure in CdTe is not satisfactory yet. New experiments on well defined samples with precisely known thermodynamic history and minimized density of unintentional impurities are requested.