The goal of this paper is to study the effect of superheating and fast cooling conditions on the defects of CdZnTe crystals especially Te inclusions. The paper reports characterization of the crystal defects using IR microscopy and Fourier Transform Infrared spectroscopy. Three ingots of CdZnTe doped with Indium were grown by Vertical Gradient Freezing. Ingot A and B were grown with superheating temperatures of 26 degrees C and 56 degrees C respectively. In the last case the growth process was followed by a fast cooling. The results show that the size of Te inclusions was greatly reduced and the crystal quality was improved after higher superheating and fast cooling. (C) 2012 Elsevier B.V. All rights reserved.