Growth and properties of In0.52Al0.48As/In0.53Ga0.47As, GaAS: In and InGaAs/GaAs multilayers

Abstract

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 In0.52Al0.48As grown on InP. This lattice-matched alloy In0.52Al0.48As may be clustered under normal growth conditions at a substrate temperature ~ 500[deg]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 In0.2Ga0.8As/GaAs strained-layer superlattices.