Defect Structure Modification in Undoped and In-doped CdTe by Cd-Rich Annealing

The effect of Cd-rich annealing at 500°C and 600°C on electrical and optical properties of undoped and high-resistivity In-doped CdTe was investigated by the Hall effect, photoluminescence and infrared transmittance measurements in the temperature interval 4.2-300 K. Formation of a conductive r-type skin layer was observed in both materials and the In Cd donor is found to be responsible for the n-type behaviour. Purification of the skin layer from fast diffusing elements was observed by photoluminescence, where a reduction of the intensity of the emission lines related to excitons bound to acceptors was detected