Numerical simulation of long wavelength photovoltaic HgCdTe photodiodes

In the paper the performance of n-on-p long wavelength photovoltaic Hg_1-xCd_xTe (x=0.224) photodiode has been simulated numerically. Calculation is based on 2D model for the backside-illuminated configuration. The influence of several factors, including p-type region thickness, the distance from p-type region contact to n⁺ area, n-side doping profile, and lifetime of electron, on R₀A product and zero-bias photocurrent is studied. Simulation results show that R₀A product decreases with increase in thickness of the p-type region. As the distance from p-type region contact to n⁺ area increases, R₀A product increases, but quantum efficiency deceases, the optimized distance is about 100μm. The performance of photodiode is strongly dependent on minority carrier (electron) lifetime, but n-side doping profile is less important.