Effect of dislocations on the zero-bias resistance-area product, quantum efficiency, and spectral response of lwir hgcdte photovoltaic detectors

The effect of dislocations on the zero-bias resistance-area product, quantum efficiency, and spectral response of long wavelength infrared (LWIR) HgCdTe photodiodes has been modeled for a case in which the line dislocations are along the thickness of the wafer. The model focuses on the calculation of the impedance of individual dislocation followed by the calculation of the resultant effect by assuming the dislocations to be uniformly distributed in the sample. In the process, we have also obtained a new relation for estimating effective diffusion length of minority carriers as a function of dislocation density in the sample. The proposed model has been shown to provide an excellent fit to the experimental data.