Impurities in three cadmium zinc telluride (Cd1-xZnxTe or CZT) ingots grown by the modified vertical Bridgman (MVB) method were examined by using inductively coupled plasma mass spectrometry (ICP-MS). The distribution and segregation of impurities along the CZT ingots were found to vary with the concentration and the growth conditions. Photoluminescence (PL) and voltage-current measurements were performed to evaluate the effects of the impurities on the optical and electrical properties. The red shift of the (D, X) and DAP positions and the broadening of the DAP band in PL spectrum were observed in the high-impurity CZT ingot. The voltage-current measurement shows a higher resistivity when the impurity concentration was increased. The above results imply that the high-impurity CZT ingot was highly compensated. (c) 2007 Elsevier B.V. All rights reserved.