Optical investigation of GaAs/InGaP heterointerfaces grown by metalorganic vapor phase epitaxy

Abstract

The characteristics of GaAs/InGaP heterostructures grown on exact (001), (Oaf) oriented 6 degrees off toward (111)A, and (112)B GaAs substrates by metal-organic vapor phase epitaxy were investigated by photoluminescence. All samples studied exhibited anomalous optical behaviors, that is, strong luminescence peaks below the GaAs band edge. It is observed that when thin GaAsP layer is grown in-between the GaAs and InGaP, the GaAs band edge emission is recovered. From the results, we conclude that the below GaAs band edge luminescence from the GaAs-on-InGaP interface is from the InGaAs formed at the interface by In carryover from InGaP to GaAs layer.