DC photoconductivity study of semi-insulating Cd1-xZnxTe crystals

Room temperature direct current (DC) photocurrents were measured for detect or grade Cd1-xZnxTe (CZT) crystals in the spectral range of 400-1000 nm as a function of light intensity and voltage. The photocurrent data were analy zed and fit to a theoretical model to extract the electrical transport prop erties for high-resistivity detector grade CZT material. Using the DC photo current measurements, the mobility-lifetime (mu tau) products and the surfa ce recombination velocities for both electrons and holes were measured. For this study the CZT detectors had Au contacts, and the surfaces were treate d in a standard 5% bromine in methanol etching solution. The correlation of the DC photocurrent measurements and detector performance is also reported .