Abstract

We study the secondary emission due to recombination of excitons near the indirect band bottom, where the relaxation is governed by the multiple scattering by acoustic phonons and a nonradiative decay process. In this case, the secondary emission can be separated exactly into the Raman scattering (S_R) and the hot luminescence (S_L) parts.^1,2) General expressions of the excitation spectrum (I_R) of S_R and the lineshape of S_L are presented. The nonradiative decay is attributed to the scattering by imperfections, and therefore the decay rate σ represents the sample dependence. Near the band bottom, the scattering by acoustic phonons is quite sensitive to temperature and the kinetic energy of exciton (E_ac) moving with the sound velocity. From the temperature dependence of I_R, we can determine σ and E_ac uniquely. It should be emphasized that in our theory, only σ and E_ac values are necessary for the calculation of S_L.

© 1984 Optical Society of America