Photoluminescence and radiative lifetime of trions in GaAs quantum wells

Electron-trion photoluminescence spectra were measured in undoped high-quality GaAs quantum wells. The obtained line shape depends on temperature and is asymmetric with a tail towards lower photon energies. For a detailed understanding, we have solved numerically the trion Schr\"odinger equation in the quantum well. Both electron and hole trions are considered. Good agreement is found for the trion binding energy and for the luminescence line shape at different temperatures. The radiative lifetime of thermalized trions is found to increase linearly with temperature. Analytical results are given for both types of trions taking into account the finite photon wave vector (light-cone effect).