The growth of high quality GaAsSb and type-II InGaAs/GaAsSb superlattice structure

Abstract

The effects of growth temperature and V/III flux ratio on the GaAsSb crystalline quality were studied. Phase separation was suppressed within a narrow window of growth temperature. 1-μm-thick GaAsSb layers which exhibited single peaks in X-ray diffraction (XRD) measurement were successfully obtained grown at the optimum temperature. XRD and photoluminescence (PL) measurements revealed that V/III flux ratio also has an optimum value. It was found that the type-II InGaAs/GaAsSb superlattice with GaAsSb grown at the optimized growth condition seems to have an excellent optical property, because the PL peak energy exhibited peculiar dependence on temperature suggesting transition between the conduction band of InGaAs and the valance band of GaAsSb.

Evidence of carrier localization in photoluminescence spectroscopy studies of mid-wavelength infrared InAs/InAs1−Sb type-II superlattices

“…The PL peak blue shift with increasing temperature below 60 K for sample A, as shown in Fig. 2(a), has been reported in ternary (GaAsBi, 16 GaInP 2 , 17 and GaAsN 18 ), quantum well (QW) (GaSb/GaAs, 19 InAs/GaSb, 20 and GaAsSbN/GaAs 21,22 ) and SL (InAs/GaSb, 23 InGaAs/GaAsSb, 24 InGaN/AlGaN 25 ) materials. Two explanations have been assigned to this behavior in the literature.…”

“…The first explanation assumed the PL was due to a band-to-band transition and attributed the peak position blue shift to the type-II QW joint density of states convolved with the thermal distribution of carriers. 19,20,23,24 Using the type-II QW absorption coefficient, 26 which is proportional to (E -E g ) 3/2 , and the Boltzmann distribution, the PL peak was expected to differ from the effective band gap by 3/2kT (E g -E PL = 3/2kT). 19 For sample A, the PL peak difference from the effective SL bandgap, (E g calculated using the Varshni equation) E g -E PL , below 60 K follows ~3kT rather than 3/2kT.…”

Near Full-Composition-Range High-Quality GaAs1–xSbx Nanowires Grown by Molecular-Beam Epitaxy

“…As one of the most important narrow-bandgap ternary alloy semiconductors, GaAs 1– x Sb x has a bandgap tunable over a large range from about 870 nm (GaAs) to 1720 nm (GaSb) at room temperature, which makes it an attractive material for band structure engineering − and various optoelectronic applications, such as in optical fiber communication systems, infrared light-emitting diodes, photodetectors, lasers, ,, and heterojunction bipolar transistors . In addition, the GaAs 1– x Sb x semiconductor alloy is also a good candidate for study on spintronic devices based on GaAs. − However, the fabrication of high-quality and high Sb content GaAs 1– x Sb x films remains a challenge because there is a large lattice mismatch between the GaAs 1– x Sb x films and III–V semiconductor substrates, and the crystalline quality of the films is very sensitive to growth conditions. ,, …”

Staggered band gap n+In0.5Ga0.5As/p+GaAs0.5Sb0.5 Esaki diode investigations for TFET device predictions

“…Based on this, the optimal growth temperature for GaAs 0.5 Sb 0.5 is defined at 470 1C which has already shown to prevent phase separation for this material [19] but also a convenient temperature for In 0.5 Ga 0.5 As growth [20]. In order to study the structural quality of the GaAs 0.5 Sb 0.5 growth on (001) InP, XRD and TEM analyses are performed.…”