STRESS BIREFRINGENCE AND MICROINCLUSIONS IN SUBLIMATION-GROWN BULK CDTE

High quality CdTe bulk crystals are difficult to obtain due to various types of defects such as twins, dislocations, inclusions, and sub-gra in boundaries. In this paper, the influence of different dopants and g rowth conditions on formation, frequency, and stereometry of those def ects are discussed. The crystals have been grown by means of a sublima tion travelling heater method (STHM) using Bridgman seeds. As dopants, the halogens chlorine, bromine, and iodine as well as vanadium and ti tanium have been used. By means of quantitative near-IR polarizing mic roscopy, the mapping of long-range stress fields can be related to irr egularities in crystal growth. Additionally, local stress birefringenc e induced by dislocations and inclusions has been observed. The occurr ence of crystal perturbations in STHM and Bridgman material is compare d.