ROOM-TEMPERATURE PHOTOREFLECTANCE AS A POWERFUL TOOL TO CHARACTERIZE THE CRYSTALLINE QUALITY OF INALAS LAYERS GROWN ON INP SUBSTRATES

The aim of this work is to show that room temperature photoreflectance can give the same indications as low temperature photoluminescence ab out the crystalline quality of both layers and interfaces. Our samples consist of molecular beam epitaxy InAlAs layers lattice-matched to In P substrates, grown at different growth temperatures and using differe nt InP cleaning temperatures. The photoreflectance broadening paramete r (Gamma) has been determined and compared with the well-known linewid th broadening of the photoluminescence. Both methods indicate that the best InAlAs crystalline quality is obtained for a growth temperature of 530 degrees C and an InP surface cleaning temperature of 530 degree s C.