Deformation-induced defects in semi-insulating CdTe and CdZnTe were studied using infra-red photoluminescence, contact-less photoconductivity and resistivity techniques. Plastic deformation increased the concentrations of grown-in defects, namely, those of an important mid-gap level EC−0.74eV in CdTe and Cd1−xZnxTe (x<0.1), the materials of choice in today’s X-ray and gamma ray detector technology. A direct correlation between Y-emission and the dislocation density was confirmed for both compounds. The Y-band intensified near an indenter deformation or near a scribing line, but was barely visible in low-dislocation areas (etch pit density <2 x 105/cm2). The results correlated with previous findings that dislocation-induced defects and their clusters degrade charge collection in radiation detectors. Photoluminescence of mid-gap levels could identify areas of degraded performance in semi-insulating CdTe and CdZnTe crystals.

Photoluminescence and Electric Spectroscopy of Dislocation-Induced Electronic Levels in Semi-Insulated CdTe and CdZnTe. V.Babentsov, V.Boiko, G.A.Schepelskii, R.B.James, J.Franc, J.Procházka, P.Hlídek: Journal of Luminescence, 2010, 130[8], 1425-30