Numerical Analysis of Radiative Recombination in Narrow-Gap Semiconductors Using the Green’s Function Formalism
A numerical model based on the Green’s function formalism has been developed and used to investigate the radiative recombination processes in multiple narrow-gap semiconductor materials. Full band structures and adaptive band-dependent tetrahedral meshes were adopted to improve the accuracy of the calculation. As a validation, the spectrum of the absorption coefficient for germanium was examined, giving good agreement with the experimental data. The absorption coefficient and radiative recombination lifetime for HgCdTe were then investigated for different compositions, carrier concentrations, and operating temperatures. The results confirmed the accuracy of the widely used theoretical formula for the radiative recombination lifetime under the condition that the effective mass of holes in the formula must be carefully chosen. Based on all our comparisons and calculations, the Green’s function model is proved to be a reliable tool for predicting the radiative recombination properties of HgCdTe, which could further facilitate the investigation of more complicated processes such as photon-recycling issues.