Investigation of CdZnTe crystal defects using scanning probe microscopy

Surface electronic properties of $Cd0.9Zn0.1Te$ (CZT) crystals have been characterized using scanning spreading resistance microscopy (SSRM) and correlated with IR transmittance maps. SSRM performed on CZT samples showed excellent correlation with Te precipitates determined from infrared images. The average probe current was observed to be more than two orders of magnitude higher for the sample with higher Te precipitates. Stationary probe current-voltage relationship was found to be exponential and was modeled based on thermionic emission theory. Based on this model, the surface barriers of the CZT samples were found to be significantly different, which was confirmed independently from Kelvin probe measurements.