Electronic and structural properties of the selectively wet-oxidized AlAs-GaAs interface

Abstract

Vertical-cavity laser thresholds have recently been greatly reduced by replacing proton implantation with selective 'wet oxidation' of the AlAs layers. The oxide provides lateral confinement of both the electrical current and the optical model. At present, little has been reported about the structure or electronic properties of the oxide and its interface with the remaining semiconductor. By measuring time-resolved photoluminescence at the GaAs band edge, it is shown that the interface recombination at the GaAs/oxide interface is strong. Furthermore, the structural properties of the oxide are investigated as these are important to the operation and longevity of oxide VCELs.