The Nature of Auger Recombination in Type-I Quantum Well Lasers Operating in the Mid-Infrared

Auger recombination is known to be a significant non-radiative process limiting near- and mid-infrared quantum well lasers. The one-dimensional confinement of quantum wells and small band offsets (relative to the bandgap) permits two fundamentally different categories of Auger mechanisms to operate. These mechanisms may be identified as either
activated
or
thresholdless
in nature. In this work, we investigate the nature of the dominant Auger mechanism in mid-infrared emitting quantum wells by characterizing a range of type-I InGaAsSb quantum well lasers operating within the 2 - 3 μm wavelength range. The temperature dependence of both the threshold current density and integrated spontaneous emission reveal that the threshold current is dominated by radiative recombination up to a break-point temperature (occurring below 200 K). Beyond the break point temperature, the exponential dependence of the threshold current increases rapidly. The deterioration in the stability of lasing threshold indicates that a thermally activated Auger process is dominant in all devices and is sensitive to the population of heavy-holes in the quantum wells.