Room temperature photoreflectance as a powerful tool to characterize the crystalline quality of InAlAs layers grown on InP substrates

Abstract The aim of this work is to show that room temperature photoreflectance can give the same indications as low temperature photoluminescence about the crystalline quality of both layers and interfaces. Our samples consist of molecular beam epitaxy InAlAs layers lattice-matched to InP substrates, grown at different growth temperatures and using different InP cleaning temperatures. The photoreflectance broadening parameter (γ) has been determined and compared with the well-known linewidth broadening of the photoluminescence. Both methods indicate that the best InAlAs crystalline quality is obtained for a growth temperature of 530 ° and an InP surface cleaning temperature of 530 °.