Nanostructures of defects in CdZnTe single crystals

Nanostructures of Cd_1-xZn_xTe (CZT) grown by the vertical Bridgman method have been studied. Selected area diffraction patterns from various local areas indicate the homogenous zinc-blende structure of CZT crystals with the lattice constant of 6.442±0.003 Å. High-resolution electron microscopy micrographs have demonstrated two distinct nanostructures for dislocations in CZT. One has an extra line of atoms and the other shows a half atom-spacing shear displacement. The former has one order of magnitude lower density than the latter, indicating that it has much higher formation energy. Te precipitates also show two types of nanostructures including ellipse shaped and linear ones that are dependent on the Te-rich percentage in the precipitates. High Te-rich precipitates have an ellipse-shaped structure while the low Te-rich ones have a linear shape. Twins in CZT are usually grouped in 3-6 microtwins parallel to each other with twinning planes lying exclusively in CZT {1 1 1} planes.