Impact of recombination centers on the spontaneous emission of semiconductors under steady-state and transient conditions

We show that recombination centers may affect the spontaneous emission of semiconductors in a different way depending on whether steady-state or transient conditions are established. This asymmetry is an inherent property of recombination centers. Recent publications concerned with this subject have, deliberately or not, ignored the asymmetry between these conditions, and have treated these physically distinct situations as being equivalent. Such a presumption may result in orders-of-magnitude errors when analyzing experimental data. Furthermore, the threshold of stimulated emission is not a unique property of the material under investigation, but is strongly dependent on the experimental conditions employed.