An investigation on optical properties of CdZnte substrate by laser irradiation.

Cadmium Zinc Telluride (Cd_0.96Zn_0.04Te) single crystals grown by Vertical Bridgman technique possess good structural quality and low defect density. Such CdZnTe crystals can be used as substrate to find applications in fabricating Infrared (IR) detectors. In this paper we discuss results obtained on effect of laser (~532nm) exposure on the Raman and Photoluminescence (PL) spectrum over polished and annealed CdZnTe substrates. The incident laser power causes the increase in Raman signal of Tellurium in CdZnTe substrate and PL emission diminishes due to the burning of semiconducting material. After laser exposure of 3 mW due to localized heating only Te element left at the laser exposure area, therefore prominent Raman modes A1 (122 cm⁻¹) and E1 (142 cm⁻¹) appeared in the sample. Raman and PL mapping confirms the formation of Te-Te bond near the laser exposure area at the CdZnTe substrate. [ABSTRACT FROM AUTHOR]