Modeling of Two-color HgCdTe Detectors

In this paper the performance of two-color middle wavelength infrared photovoltaic HgCdTe detector is simulated numerically based on two-dimensional model. Structure of n-p-p-p-n is designed in simultaneous mode. Spectral response is calculated, crosstalk between two bands and the function of barrier layer are analyzed in detail. Calculation results show that the radiation in MW1(shorter wavelength in middle wavelength band) band can be absorbed in MW2(longer wavelength in middle wavelength band) diode, this causes MW1-to-MW2 crosstalk, and the crosstalk is linearly depended on the ratio of radiation power absorbed in MW2 diode to that in MW1 diode. The barrier layer can remarkably suppress the crosstalk caused by photocarriers diffusion. Without barrier layer, the MW1-to-MW2 crosstalk will increase as large as 10 times, and is dominated by photocarriers diffusion.