InAs/InAs(P,Sb) quantum-well laser structure for the midwavelength infrared region

Strained InAs1-xSbx(0 < x < 0.22) quantum wells with InAs, InAsP, or InAsPS b barrier layers have been grown by metal-organic vapour-phase deposition o n InAs substrates. Their photoluminescence and electroluminescence were stu died at 20 K. The photoluminescence peak-wavelength evolution with the anti mony composition x and the nature of the barrier were theoretically predict ed in a satisfactory manner under the assumption of a type-II band alignmen t for the InAsSb/InAs system with a valence band ratio Q(v) = -1.30. This h ypothesis leads to a type-IIa band alignment for the arsenic-rich InAsSb/In AsP system. Starting from this result, a 'W' laser structure, consisting of ten periods of InAsSb/InAsP/InAsSb/InAsPSb multiquantum wells in the activ e region, a broadened InAsPSb waveguide, and AlAsSb cladding layers, is pro posed for room-temperature emission near 3.3 mu m.