VIBRATIONAL-MODES OF CARBON-ALUMINUM COMPLEXES IN ALXGA1-XAS GROWN BY METALORGANIC MOLECULAR-BEAM EPITAXY

We investigated the effect of Al atoms on the localized vibrational mode (LVM) due to C in heavily C-doped AlGaAs grown by metalorganic molecular beam epitaxy (MOMBE). Several satellite peaks were observed in the range between 550 and 650 cm-1, instead of the C LVM at 583 cm-1, which has fine structure caused by Ga isotopes. We conclude these satellite peaks are due to C atoms perturbed by the surrounding Al atoms. Also, the C fine structure was not observed in heavily C-doped GaAs grown by MOMBE. We further conclude that the C fine structure cannot be observed in heavily C-doped AlGaAs because of strong perturbation from the surrounding Al and C atoms.