MOMENTUM CONSERVATION OF THE ELECTRON-HOLE RECOMBINATION NEAR THE ONE-COMPONENT TO 2-COMPONENT CARRIER PLASMA TRANSITION

The relaxation of momentum conservation in the one-component electron plasma recombination has been investigated in GaInAs modulation doped quantum wells where holes are spatially localized at acceptor sites purposely introduced in the wells. The saturation of the localization centers by high-intensity optical excitation results in the recovery of the usual k-conserving recombination process. A theoretical model taking into account the competition of k-conserving and k-nonconserving processes is proposed to obtain the relevant energetic parameters of the carrier plasma. Finally, the transition from an electron to an electron-hole plasma is evidenced through the analysis of the band filling luminescence spectra.