摘要： Type-I quantum well (QW) lasers based on the GaSb material system show attractive characteristics in the mid-infrared [1]. However, as the wavelength (λ) increases in the range of 2-4 μm their performance begins to deteriorate due to increasing Auger recombination [2]. In the Auger process, the energy released from an electron-hole recombination is transferred to a third carrier. In order to develop strategies to suppress Auger recombination, it is crucial to understand the magnitude and nature of the dominant Auger recombination pathway, and their dependencies on the operating λ and temperature (T). In QW structures two fundamentally different Auger process can occur [3]. In an activated Auger process, initial and final carrier states are confined to the plane of the QW. The recombination rate due to this process depends exponentially on T because it is determined by an activation energy, which is a consequence of energy and momentum conservation. In a thresholdless Auger process, the initial carrier states can exist near the band edge (bottom of conduction/valence band) and the third carrier is excited into the continuum of unbound states in a direction perpendicular to the plane of the well. Without an activation energy, the thresholdless Auger process exhibits only a weak T dependence. In this work, we report on the T and λ dependence of the threshold current density (Jth) of type-I QW devices operating in range 1.95-3.2 μm. From T-dependent measurements, we find that radiative recombination dominates from low T up to a break point temperature [4]. Beyond this break point the temperature sensitivity of Jth increases rapidly, indicating the onset of a strongly temperature-sensitive activated Auger process. Using hydrostatic pressure, we tune the operating λ of the lasers in order to probe the λ dependence of the Auger coefficient. Modelling the gain and loss characteristics of the lasers allowed the threshold carrier density (nth) to be determined. Since the carrier density calculations depend sensitively on the threshold gain, we undertook segmented contact measurements to experimentally determine the optical loss. By extracting the experimentally-determined radiative component of Jth and assuming the remaining non-radiative current (cid:1836)(cid:1866)(cid:1870)=(cid:1829)(cid:1866)(cid:1872)?, C and its λ dependence were calculated, although the analysis also provides evidence that the dependence is not strictly cubic (i.e., C depends on nth).