Carrier recombination dynamics in a (GaInSb/InAs)/AlGaSb superlattice multiple quantum well

Abstract

We have used the 830 nm, subpicosecond output of a mode-locked Ti:sapphire laser, together with subpicosecond 3.55 m pulses from a synchronously pumped optical parametric oscillator, to perform room-temperature, time-resolved, differential transmission measurements on a multiple quantum well structure with AlGaSb barriers and GaInSb/InAs superlattice wells. From these measurements, we have determined a Shockley-Read-Hall rate of 2.4ϫ10 8 s Ϫ1 and an Auger coefficient of 7ϫ10 Ϫ27 cm 6 /s. In addition, we estimate the carrier capture efficiency into the wells to be ϳ52% and have demonstrated that carrier cooling, cross-well transport, and capture are complete within ϳ10 ps after excitation.

Modeling of Recombination in HgCdTe

“…Typical agreement with measured absorption spectra for superlattices is 10% to 50%. 12,13 Auger recombination rate calculations, which are computationally more intensive, require additional approximations and are thus characteristically less accurate than the optical properties. Despite these approximations, we have demonstrated agreement of better than a factor of two between theoretically and experimentally determined Auger rates in a wide variety of MWIR and LWIR superlattices and bulk materials.…”

“…We typically achieve roughly a factor of two agreement between theoretically predicted and experimentally determined Auger lifetimes in Sb-based narrow-gap superlattices. 13,14,18 Radiative lifetimes were also computed employing directly the band structures and matrix elements from the 14-band k AE p formalism, and evaluated with the standard van Roosbroeck-Shockley expression that does not take photon recycling into account. 19 Defect-mediated recombination is not included in the calculations, hence the reported lifetimes are theoretical upper bounds designed to provide guidance to experimental programs in assessing their materials quality.…”

Room Temperature Carrier Kinetics in the W-type GaInAsSb/InAs/AlSb Quantum Well Structure Emitting in Mid-Infrared Spectral Range

“…The long lasting component of the TRR signal, tracked up to 1.6 ns, is attributed to the radiative recombination of spatially separated electron-hole pairs (electrons in the InAs layer and holes in Ga 0.80 In 0.20 As 0.15 Sb 0.85 ). It is expected that the radiative recombination of an electronhole pair at room temperature in these type-II quantum wells can reach an average value of a few to tens of ns [2,[4][5][6]. The most intriguing and not observed before relaxation channel is indicated by the short decay component of the TRR signal.…”

“…quantum cascade lasers, in some performances. In spite of that, some of the properties of the active region in this experimentally demanding spectral range are still not well known, and this concerns also carrier dynamics, on which only very initial works have been reported in the 90's [2][3][4][5][6].…”

“…Several types of experimental methods have been used in order to study carrier dynamics in QW systems of that kind, including: time-resolved differential transmission [2,5], time-resolved photoluminescence up-conversion [3,5,6], or photoconductive response technique [4]. All of them employ highly intensive laser pulses in order to track carrier relaxation processes in multiple QWs of the considered * corresponding author; e-mail: marcin.syperek@pwr.edu.pl type.…”