Photocurrent effect on the zero-bias dynamic resistance of HgCdTe photodiode

Abstract

A new physical model is presented for the illumination-dependence of the zero-bias resistance-area product (R(o)A) Of HgCdTE photodiode. The model is based on three independent mechanisms. They are the depletion region volume change with the applied bias, the diffusion distance change with the moving depletion region edge, and the minority carrier accumulation in the depletion region which affects the minority earlier diffusion. Analytic equations are derived far the photodiode current-voltage characteristics and R(o)A products. The results Of the model have been compared with experimental data obtained from several Hg0.7Cd0.3Te diodes with an identical diode structure having different absorbing amount of light. The model showed good agreement with the experimental data.