Stimulated recombination in highly excited GaAs

Abstract
We consider various theoretical approaches to the evaluation of radiative-recombination spectra in semiconductors. In particular, we analyze in detail the finite-temperature Matsubara and Keldysh procedures and demonstrate explicitly that after suitable modifications the two methods yield identical results for the optical gain. We include correlation effects and the correct band structure in our calculation. Our results for the stimulated emission are in good agreement with experiment and yield new estimates for the carrier-density dependence of the total radiative-recombination lifetime.