InAsSb/InPSb Strained-Layer Superlattice Growth Using Metal-Organic Chemical Vapor Deposition

The authors report on the metal-organic chemical vapor deposition (MOCVD) of strained layer superlattices (SLSs) of InAsSb/InPSb as well as mid-infrared optically pumped lasers grown using a high speed rotating disk-reactor (RDR). The devices contain AlAsSb cladding layers and strained, type I, InAsSb/InPSb active regions. By changing the layer thickness and composition of InAsSb/InPSb SLSs, they have prepared structures with low temperature (< 20 K) photoluminescence wavelengths ranging from 3.4 to 4.8 {micro}m. They find a variation in bandgap of 0.272 to 0.324 eV for layer thicknesses of 9.0 to 18.2 nm. From these data they have estimated a valence band offset for the InAsSb/InPSb interface of about 400 meV. The optical properties of the superlattices revealed an anomalous low energy transition that can be assigned to an antimony rich interfacial layer in the superlattice. An InAsSb/InPSb SLS, laser was grown on an InAs substrate with AlAs{sub 0.16}Sb{sub 0.84} cladding layers. A lasing threshold and spectrally narrowed laser emission were seen from 80 through 200 K, the maximum temperature where lasing occurred. The temperature dependence of the SLS laser threshold is described by a characteristic temperature, T{sub 0} = 72 K, from 80 to 200 K