Characterization of cadmium-zinc telluride crystals grown by 'contactless' PVT using synchrotron white beam topography

Crystals of Cd_{1 - x}Zn_xTe grown by PVT using self-seeding 'contactless' technique were characterized using synchrotron radiation (reflection, transmission, and Laue back-reflection X-ray topography). Crystals of low (x = 0.04) and high (up to x ≈ 0.4) ZnTe content were investigated. Twins and defects such as dislocations, precipitates, and slip bands were identified. Extensive inhomogeneous strains present in some samples were found to be generated by interaction (sticking) with the pedestal and by composition gradients in the crystals. Large (up to about 5 mm) oval strain fields were observed around some Te precipitates. Low angle grain boundaries were found only in higher ZnTe content (x ≥ 0.2) samples.