TEM and photoluminescence characterization of ordered domains in Ga0.51In0.49P alloys

Transmission electron microscopy (TEM), photoluminescence (PL) and polarized photoluminescence excitation (PLE) spectroscopy, have been performed on MOCVD grown GaInP2 layers differently misoriented on (001) GaAs. The layers spontaneously order in CuPtB variants. The more misosoriented samples' show a higher structural order and a sharper distribution of the ordering degree in the CuPt domains. The more relevant parameters suggesting a direct relation between CuPt structure and electronic energy gap are the crystal held split-off energy of the valence band and the band-to-band transition onset in the PLE spectra.