Recombination channels in 2.4-3.2 μm GaInAsSb quantum-well lasers

Spontaneous emission has been used to evaluate the proportion of the different recombination channels in 2.4-3.2 mu m type I-GaInAsSb quantum-well lasers operating at room temperature. The method consists in using the square root of the integrated spontaneous emission rate as a value proportional to the carrier density. A second-degree polynomial relationship can then be used to determine the proportion of the different recombination currents (monomolecular, radiative and Auger) in a laser diode operated below threshold. A notable increase of the Auger recombination has been observed with increasing wavelength. Auger recombination currents account for only 26% of the total current at threshold at 2.4 mu m, while the proportion reaches 55% at 2.8 mu m and 64% at 3.2 mu m.