Two important observations for porous silicon, the saturation and the voltage selective quenching of photoluminescence, are presented. Their similarities are pointed out and discussed in two phenomenological models: the saturation of the absorption and an Auger effect. The consequences of carrier accumulation in quantum crystallites are emphasized in both cases. The rate of Auger recombination in quantum crystallites is calculated theoretically and is compared to experiments. The importance of the Auger effect is then checked in the mechanisms of the voltage tunable electroluminescence.

• Received 30 September 1994

DOI:https://doi.org/10.1103/PhysRevB.51.17605