[show abstract][hide abstract] ABSTRACT: The scanning spreading resistance microscopy characterization of surface electronic properties of Cd0.9Zn0.1Te (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.
Semiconductor Science and Technology 03/2009; 24(4):045012. · 1.92 Impact Factor
[show abstract][hide abstract] ABSTRACT: Surface electronic properties of CdxZnyTe were characterized through scanning spreading resistance microscopy (SSRM) and correlated IR transmittance maps. We observed the magnitude of the SSRM current is dominant by the density of surface localized Te precipitates and spatial variation of Zn content. The magnitude of the average SSRM current for forward probe bias was found to correlate strongly with the density of Te precipitates, while the variation in I-V characteristics were caused by slight p-type or n-type characteristics due to non-uniformity in Zn content of the crystal. Experimentally observed I-V characteristics were simulated using thermionic emission theory.
[show abstract][hide abstract] ABSTRACT: Surface electronic properties of Cd <sub>0.9</sub> Zn <sub>0.1</sub> Te (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.