Optical characterization and room temperature lifetime measurements of high quality MBE-grown InAsSb on GaSb

Abstract

InAs 0.91 Sb 0.09 lattice matched to a GaSb substrate by molecular beam epitaxy (MBE) is characterized by photoluminescence and photoconductivity measurements. Absorption, photoluminescence and spectrally resolved dc photoconductivity measurements lead to a band gap expression for InAs 1−x Sb x , as a function of the Sb content x, where 0.06 < x < 0.12 and the material is nearly lattice matched to GaSb. The expression is in good agreement with recent results focusing on this range of Sb content, but deviates significantly from the one known from the literature and covering the entire Sb composition range. The carrier lifetime was measured by stationary and time resolved photoconductivity with an excitation source at 3.39 µm. We report Shockley-Read limited lifetimes as long as 200 ns, which indicate the high quality of the material. The accuracy and consistency of these optical characterization techniques allow a reliable comparison of samples and provide a guide for the optimization of growth parameters.

Room temperature InAsSb photovoltaic midinfrared detector

“…1, but without any doping beyond the GaSb buffer. 5 Absorption and photocurrent in these samples increase slowly with energy above the band gap due to the small effective mass in In 0.91 As 0.09 Sb and are in good agreement with theoretical calculations, as shown in Fig. 2.…”

Growth of InAsSb/InAs MQWs on GaSb for mid-IR photodetector applications

“…Mid-infrared photodiodes (or photodiode-arrays) are of special interest, as most environmentally interesting gases/pollutants show absorption lines or bands (spectroscopic fingerprints) in this region [5,6]. The proposed devices could thus be used for monitoring gases such as CH 4 , CO 2 , CO, N 2 O and O 3 quickly and cost effectively.…”

“…Most previous reports of photodetector work in this material system involved InAsSb lattice matched to GaSb, having a band gap corresponding to 4:3 mm (0.286 eV) at room temperature [6,7]. In this work we explore the possibility of strain compensated InAs/InAsSb multi-quantum wells (MQW) grown on GaSb substrates by OMVPE.…”

Growth of InAsSb/InPSb heterojunctions for mid-IR detector applications

“…The bandgap for lattice matched growth of InPSb on GaSb is approximately 0.44 eV [3]. This compares with a room-temperature bandgap of 0.26 eV [4] for InAsSb lattice matched to GaSb. At the lattice matched composition, InPSb is well inside the miscibility gap, nevertheless, there have been several reports of this material as a barrier material for mid-IR lasers and detectors [5,6].…”