DEEP-CENTER OXYGEN-RELATED PHOTOLUMINESCENCE IN GAAS DOPED WITH DIMETHYLALUMINUM METHOXIDE DURING ORGANOMETALLIC VAPOR-PHASE EPITAXY

Infrared oxygen-related photoluminescence measurements of GaAs epilaye rs grown by organometallic vapor phase epitaxy (OMVPE) and intentional ly doped with dimethylaluminum methoxide (DMALMO) are reported. The ph otoluminescence emissions at 1.08, 0.95, 0.81, and 0.62 eV are detecte d. The centers responsible for the emissions at 0.81 and 0.62 eV are t entatively attributed to Al-O-Ga and Al-O-Al, respectively, based on c orrelation with layer growth conditions. The growth parameters lead to information on the number of nearest-neighbor aluminum associated wit h oxygen. The Al-O-Ga center responsible for the 0.81 emission is also studied for AlxGa1-xAs(x=0.05-0.9) layers grown by OMVPE without DMAL MO. The 0.81 eV emission is attributed to the transition from the cond uction band to the Al-O-Ga center. The center shows the lattice relaxa tion exemplified by the Franck-Condon shift of 0.15 eV. The thermal io nization energy of this acceptor is determined to be 0.56 eV above the valence band. (C) 1995 American Institute of Physics.