Parameter extraction of HgCdTe infrared photodiodes exhibiting Auger suppression

Abstract

In this work, finite element methods are used to obtain self-consistent, steady-state solutions of Poisson's equation and the carrier continuity equations. Experimental dark current–voltage characteristics between 120 and 300 K of HgCdTe Auger-suppressed photodiodes with cutoff wavelength of λc = 10 µm at 120 K are fitted using numerical simulations. Fitting parameters used include the overlap integral |F1F2| found to vary from 0.29 at 120 K down to 0.20 at 300 K and the Shockley–Read–Hall (SRH) characteristic lifetime found to be of the order of 10−7 s at all temperatures. Based on this fitting, negative differential resistance observed in the experimental data is attributed to full suppression of Auger-1 processes and partial suppression of Auger-7 processes. Leakage current induced by traps and impurities in the material causing SRH recombination is found to limit the saturation current after Auger suppression.