Structural and optical characterization of type-II InAs/InAs1−xSbx superlattices grown by metalorganic chemical vapor deposition

Abstract

Strain-balanced type-II InAs/InAs1–xSbx superlattices with various compositions (x = 0.22, 0.23, 0.37) and different layer thicknesses (tInAs = 7 nm, tInAsSb = 3.3, 2.3, 2.0 nm, respectively) have been grown by metalorganic chemical vapor deposition on GaSb substrates. X-ray diffraction revealed narrow satellite peaks (full-width-half-maximum of <100 arc sec), indicative of uniform superlattice periodicity and excellent crystallinity, which was also corroborated by cross-sectional transmission electron microscopy observations. Despite relaxation, low-temperature photoluminescence measurements showed peaks at 6.7 μm and 5.8 μm, while photoconductance results showed strong spectral response up to 200 K, when the photoresponse onset was 8.6 μm.

Structural properties of InAs/InAs1–xSbx type-II superlattices grown by molecular beam epitaxy

“…12 Recently, InAs/ InAs 1Àx Sb x SLs grown by metalorganic chemical vapor depostition (MOCVD) have been studied in more detail: these SLs showed excellent structural properties and strong optical response. 13,14 The absence of gallium in these InAs/ InAs 1-x Sb x SLs is expected to simplify the SL interfaces and hence the growth process, 13 and also result in longer carrier lifetimes, 15,16 as very recently demonstrated.…”

Long-wave infrared nBn photodetectors based on InAs/InAsSb type-II superlattices

“…10,11 Recently, the study of another type of T2SL, namely the "Ga-free" InAs/InAsSb T2SLs grown on GaSb substrates, has been revisited and revealed very encouraging results. [12][13][14][15] Time resolved PL measurements of the InAs/InAs 0.72 Sb 0.28 T2SL structures showed minority carrier lifetimes greater than 412 ns due to strong reduction of nonradiative recombination in these superlattices. 16 Therefore, it is reasonable to expect that substantially better photodetector performance and higher operating temperature are achievable with the InAs/InAsSb T2SL materials.…”

Raman Scattering Study of Lattice Vibrations in the Type-II Superlattice InAs/InAs1−xSbx

“…These samples were all capped with 10 nm AlSb followed by 10 nm GaSb, except for B1854 that was capped by 100 nm InAs. MBE sample EB3610 (grown at Sandia National Laboratories) was grown at ~ 420 o C. More growth details can be found elsewhere [30][31][32]. The compositions of the InAs1-xSbx alloys and InAs1-xSbx alloy layers in the SLs were determined by X-ray analyses.…”

“…The individual layers in the SL samples were found being nearly coherently strained by the substrate [31], the two relatively high Sb composition alloy samples were found to be partially relaxed (3-2483, ~75%; 3-2489, ~79%). The details of the X-ray analysis methods can be found in our previous publications [30,31]. We note that the compositions were derived under the assumption of an abrupt Sb profile.…”