Low temperature photoluminescence of Ga0.84In0.16As0.22Sb0.78 solid solutions lattice matched to InAs

Low-temperature photoluminescence (PL) study of liquid phase epitaxy grown undoped and Sn doped GaIn0.16As0.22Sb layers lattice matched to InAs is rep orted. The quaternary solid solutions Ga1-xInxAsySb1-y are promising materi als for the fabrication of optoelectronics devices operating in the spectra l range 3-5 mum because these alloys can form type II heterojunctions both with staggered and broken-gap alignment. The band structure engineering of these devices requires the knowledge of energy gaps and mechanism of radiat ive recombination transitions in the forbidden gap of cladding layers. The high quality quaternary GaIn0.16As0.22Sb epitaxial layers with low native d efect concentration were grown lattice matched to InAs and their photolumin escence was studied at low temperatures. The emission band related to bound exciton was dominant. While the emission bands associated with the first i onization state of VGaGaSb vacancy-antisite defect with activation energy D eltaE(A)=22 meV and unknown deep defect with DeltaE(B)=46 meV were found be sides the main PL peak DeltaE(BE)=16 meV. It was established that Sn as an amphoteric impurity can form shallow donor levels. (C) 2001 American Instit ute of Physics.