Investigation of nanoscale electronic properties of CdZnTe crystals by scanning spreading resistance microscopy

摘要

The scanning spreading resistance microscopy characterization of surface electronic properties of Cd_(0.9)Zn_(0.1)Te (CZT) samples was performed through large area current maps and stationary current-voltage (I-V) characteristics. A semi-insulating CZT crystal was found to have non-uniform conductivity with adjacent p- and n-type-doped regions, whereas a conducting crystal had predominantly p-type doping arising out of a high density of Te inclusions that behave as highly p-type-doped regions. Experimental I-V characteristics were simulated by the thermionic-emission model to determine the surface barrier heights of the n- and p-type regions, which are influenced by local Zn alloy composition during crystal growth.