Radiative Decay of a Trion in a Quantum Well of a Semiconductor Heterostructure

A quasi-classical model for the decay of a negative trion (exciton + electron) in a single crystalline quantum well (QW) into a c-band electron and the exciton followed by recombination of the electron and hole constituting the exciton was developed. It was shown that the trion binding energy increased if the QW quantum-sized energy levels were populated by electrons from a semiconductor matrix selectively doped with donors. Calculations established that the trion emission line width was slightly larger than that for a single exciton. The results as a whole agreed with known experimental data on the low-temperature radiative decay of trions in a QW. It was pointed out that the population of the trion quantum-sized energy levels could be changed by the application an external longitudinal (along the QW) electric field. A scheme for a stationary light-emitting device based on radiative transitions of trions (not leading to their decay) between quantum-sized energy levels was proposed.