Optical quality improvement of MOVPE grown GaAlAs/GaAs double heterostructures on silicon substrates

Abstract We report a study of metalorganic vapour phase epitaxy (MOVPE) grown GaAlAs/GaAs double heterostructures on Si substrates. The main part of this work deals with the influence of post growth annealing conditions on cathodoluminescence (CL) efficiency, defect reduction, Si distribution over the structure, and interfaces state. It has been found by 300 K cathodoluminescence measurements that treatment at high temperature up to 900°C reduces defect and deep level transitions giving rise to larger zones of high near band edge (NBE) emission luminescence in contrast to those observed on unannealed samples. Such improvement has been confirmed by transmission electron microscopy and luminescence decay measurements. Carrier life times as 6 ns have been measured indicating a ten fold increase after annealing.