Low-Temperature Dispersion of Piezobirefringence and Optical Diagnostics of Internal Mechanical Stresses in Cadmium Telluride

摘要

Dispersion dependences of the piezobirefringence (PBR) coefficient are obtained for the 100 and 111 crystallographic directions in CdTe single crystals at a temperature of practical application of photosensitive CdxHg1xTe / CdTe heterostructures (the boiling point of liquid nitrogen). At a low temperature, the PBR coefficient near the fundamental absorption edge has a significantly larger magnitude than at room temperature. From the data obtained, the possibility of a significant increase in the sensitivity of the polarization optical method for measuring internal mechanical stresses (IMS) in semiconductor crystals is substantiated. A sharp increase in IMS is found in CdTe single crystals as the temperature is lowered. The results obtained also show that the diagnostics of small-scale mechanical stresses in semiconductor crystals is possible in principle on the basis of measuring the degree of depolarization of linearly polarized radiation.