Thermal diffusion current mechanisms in n+-p-p+Hg1-xCdxTe photodiodes

Abstract

The thermal diffusion current mechanisms present in an 8-14 micrometer n⁺-p-p⁺(Hg,Cd)Te photodiode are analyzed. The n⁺region diffusion current is determined by first calculating the Auger 1 lifetime in degenerate n-type (Hg,Cd)Te. The Auger 1 lifetime is found to vary as 1/n^αo, where 0.7 ≤ α ≤ 1.0 and no is the equilibrium carrier density, for degenerate n-type (Hg,Cd)Te. The p-side diffusion current is calculated by considering the radiative and Auger 7 recombination mechanisms. A comparison of the n⁺- and p- side thermal diffusion current components reveals that the p-side contribution is dominant.