Suppression of Auger recombination in arsenic-rich InAs1−xSbx strained layer superlattices

Abstract

Room-temperature pump–probe transmission experiments have been performed on an arsenic-rich InAs/InAs1−xSbx strained layer superlattice (SLS) above the fundamental absorption edge near 10 μm, using a ps far-infrared free-electron laser. Measurements show complete bleaching at the excitation frequency, with recovery times which are found to be strongly dependent on the pump photon energy. At high excited carrier densities, corresponding to high photon energy and interband absorption coefficient, the recombination is dominated by Auger processes. A direct comparison with identical measurements on epilayers of InSb, of comparable room-temperature band gap, shows that the Auger processes have been substantially suppressed in the superlattice case as a result of both the quantum confinement and strain splittings in the SLS structure. In the nondegenerate regime, where the Auger lifetime scales as τ−1aug=C1N2e, a value of C1 some 100 times smaller is obtained for the SLS structure. The results have been interpreted in terms of an 8×8 k⋅p SLS energy band calculation, including the full dispersion for both k in plane and k parallel to the growth direction. This is the strongest example of room-temperature Auger suppression observed to date for these long-wavelength SLS alloy compositions and implies that these SLS materials may be attractive for applications as room-temperature mid-IR diode lasers.

Auger recombination in narrow-gap semiconductor superlattices

“…Finally, we have included the results of Ciesla et al 24 who measured the Auger coefficient of InSb and that of an InAs/InAs 0.68 Sb 0.32 superlattice on an InAs 0.84 Sb 0.16 relaxed buffer ͑sample IC389͒. They found an improvement of about two orders of magnitude, which definitely is not predicted by our theory.…”

Recombination Dynamics Study on Nanostructured Perovskite Light‐Emitting Devices

“…In such cases, not only better passivation of traps be provided, but the fundamental problem of large Auger recombination that is present in small nanocrystals also needs to be solved. Therefore, strategies that have been applied to reduce Auger recombination loss in other inorganic semiconductor nanocrystal systems (such as the introduction of core–shell structures, strained‐layer superlattices, or electronic structure modulations) could possibly be adopted to improve the quality of small perovskite nanocrystals, thereby boosting the performance of the perovskite LEDs …”

InAs/GaSb Type-II Superlattice Detectors

“…[100,108]. Such increases in minority carrier lifetimes, along with demonstrated band gap adjustability [109] and suppressed Auger recombination rates [110], suggest lower dark currents for InAs/InAsSb SL detectors in comparison with their InAs/GaSb T2SL counterparts. However, performance, in particular, signalto-noise ratio, of InAs/InAsSb SL-based detectors with pin [111] and nBn [112] architectures was not superior to T2SLbased devices operating in the same wavelength range.…”