Ultralow Intersubband Absorption Saturation Intensity at Communication Wavelength Achieved in Novel Strain Compensated InGaAs/AlAs/AlAsSb Quantum Wells Grown by Molecular Beam Epitaxy

Micro-Raman scattering study of InGaAs/(AlAs)/AlAsSb quantum wells grown by molecular beam epitaxy

“…The PL spectra of Sb-terminated QWs are broadened and red-shifted relative to those of the equivalent As-terminated version. In order to further improve interface quality, we have introduced several mono-layers (MLs) of AlAs between the InGaAs well and the AlAsSb barrier [5,6].…”

Mid-infrared Quantum Cascade Lasers

“…As a consequence of its very large -point conduction band offset ( E c~1 .6eV [55] [ 56,57,58]. In 0.53 Ga 0.47 As-AlAs 0.56 Sb 0.44 is of particular interest because, in contrast to the InAs/AlSb system described in the next section, it not only provides a large E c , but also provides lattice-matched compatibility with established InP low-loss waveguide design and device fabrication technology.…”

“…In addition, even if perfect lattice matching is achieved, the conduction band offset is influenced by the intrinsic interface strain which is another consequence of the difference in both Group III and Group V species in the well and barrier [60]. Nevertheless, it has been convincingly demonstrated, principally by Mozume and co-workers [55,56,58 [61]. Samples with 20 active periods, either of the 3 quantum well or 4 quantum well (double phonon resonance) design were produced ( Figure 12), with intended emission wavelengths between 2.9 and 4.8µm.…”

Femtosecond pump-probe spectroscopy of intersubband relaxation dynamics in narrow InGaAs∕AlAsSb quantum well structures

“…7͒ or InP substrates, 8 In 0.53 Ga 0.47 As/ AlAs 0.56 Sb 0.44 lattice matched to InP, 9,10 InAs/ AlSb on GaSb, 5 or nitrides such as InGaN / AlGaN ͑Refs. 11 and 12͒ and II-VI compounds such as ZnSe/ BeTe.…”

“…15 We employ femtosecond pump-probe spectroscopy and focus on the possible role of intervalley electron transfer in the relaxation dynamics. Though time resolved experiments on this material system have been reported before, 10 the role of indirect states has remained open. The shortest lasing wavelength in this material system to date is around 3.8 m, 15 but electroluminescence down to 3.1 m has been observed 17 despite the fact that at this wavelength the excited subband is supposed to lie already above the lowest X state in the InGaAs QW.…”