GROWTH AND PROPERTIES OF IN0.52AL0.48AS/IN0.53GA0.47AS, GAAS-IN AND INGAAS GAAS MULTILAYERS

We have investigated the properties of some In-containing materials and heterostructures grown by molecular beam epitaxy on GaAs and InP substrates. Photoluminescence spectra of InGaAs/InAlAs quantum wells have been related to growth kinetics and it is seen that growth interruption or the incorporation of a few periods of superlattices at the heterointerfaces smooths the growth front. Experiments have been performed to determine the properties of In//0//. //5//2Al//. //0//4//8As grown on InP. This lattice-matched alloy In//0//. //5//2Al//0//. //4//8As may be clustered under normal growth conditions at a substrate temperature approximately 500 degree C. Addition of small amounts of In(0. 2-1. 2%) to GaAs reduces trap and defect densities in these materials, as seen from DLTs and low-temperature photoluminescence data. The improvement may be related to the higher surface migration rate of In compared to Ga and a subsequent reduction of point defects. Single-mode optical guides and direction couplers with losses as low as 1-3 db/cm have been fabricated with GaAs:In and In//0//. //2Ga//0//. //8As/GaAs strained-layer superlattices.