Metamorphic InAs(Sb)/InGaAs/InAlAs nanoheterostructures grown on GaAs for efficient mid-IR emitters

Publication date: Available online 12 December 2018Source: Progress in Crystal Growth and Characterization of MaterialsAuthor(s): S.V. Ivanov, M.Yu. Chernov, V.A. Solov'ev, P.N. Brunkov, D.D. Firsov, O.S. KomkovAbstractHigh-efficiency semiconductor lasers and light-emitting diodes operating in the 3–5 μm mid-infrared (mid-IR) spectral range are currently of great demand for a wide variety of applications, in particular, gas sensing, noninvasive medical tests, IR spectroscopy etc. III-V compounds with a lattice constant of about 6.1 Å are traditionally used for this spectral range. The attractive idea to fabricate such emitters on GaAs substrates by using In(Ga,Al)As compounds is restricted by either the minimum operating wavelength of ∼8 μm in case of pseudomorphic AlGaAs-based quantum cascade lasers or requires utilization of thick metamorphic InxAl1-xAs buffer layers (MBLs) playing a key role in reducing the density of threading dislocations (TDs) in an active region, which otherwise result in a strong decay of the quantum efficiency of such mid-IR emitters. In this review we present the results of careful investigations of employing the convex-graded InxAl1-xAs MBLs for fabrication by molecular beam epitaxy on GaAs (001) substrates of In(Ga,Al)As heterostructures with a combined type-II/type-I InSb/InAs/InGaAs quantum well (QW) for efficient mid-IR emitters (3–3.6 μm). The issues of strain relaxation, elastic stress balance, efficiency of radiative and no...
Source: Progress in Crystal Growth and Characterization of Materials - Category: Chemistry Source Type: research