Direct and phonon-assisted indirect Auger and radiative recombination lifetime in HgCdTe, InAsSb, and InGaAs computed using Green's function formalism

Abstract

Direct and phonon-assisted (PA) indirect Auger and radiative recombination lifetime in HgCdTe, InAsSb, and InGaAs is calculated and compared under different lattice temperatures and doping concentrations. Using the Green's function theory, the electron self energy computed from the electron-phonon interaction is incorporated into the quantum-mechanical expressions of Auger and radiative recombination, which renders the corresponding minority carrier lifetime in the materials due to both direct and PA indirect processes. Specifically, the results of two pairs of materials, namely, InAs0.91Sb0.09, Hg0.67Cd0.33Te and In0.53Ga0.47As, Hg0.38Cd0.62Te with cutoff wavelengths of 4 μm and 1.7 μm at 200 K and 300 K, respectively, are presented. It is shown that for InAs0.91Sb0.09 and Hg0.67Cd0.33Te, when the lattice temperature falls below 250 K the radiative process becomes the limiting factor of carrier lifetime in both materials at an n-type doping of 1015cm-3, while at a constant temperature of 200 K, a high n-type doping (ND > 5 × 1015cm-3 for InAs0.91Sb0.09 and 3 × 1015cm-3 for Hg0.67Cd0.33Te) makes the Auger process dominate. For the Auger lifetime in In0.53Ga0.47As and Hg0.38Cd0.62Te, the calculation suggested that under all the temperatures and n-doping concentrations investigated in this paper, radiative process is always the limiting factor of the materials' minority carrier lifetime. The calculation of the PA indirect Auger process in the four materials further demonstrated its indispensable contribution to the materials' total Auger rate especially at low temperature, which is necessary to reproduce some experimental data. By fitting the Beattie-Landsberg-Blakemore (BLB) formula to the numerical Auger results, the corresponding overlap integral factors | F 1 F 2 | in BLB theory are evaluated and presented to facilitate fast and accurate Auger calculations in the IR detector simulations.