Defects in cadmium zinc telluride crystals revealed by etch-pit distributions

We demonstrated the distribution of defects in cadmium zinc telluride (CZT) detectors by revealing etch pits on the surfaces with a chemical-etching method and Te inclusions in the bulk of the crystals. The dislocation networks observed from etch pits on the crystals’ surfaces were traced down within the bulk by removing the material layer by layer, followed by sequential Nakagawa etching. We also identified the etch pits corresponding to Te inclusions, and correlated them with grain boundaries and dislocation lines.