Deep-center oxygen-related photoluminescence in GaAs doped with dimethylaluminum methoxide during organometallic vapor phase epitaxy

Abstract

Infrared oxygen-related photoluminescence measurements of GaAs epilayers grown by organometallic vapor phase epitaxy (OMVPEj and intentionally doped with dimethylaluminum methoxide (DMALMO) are reported. The photoluminescence emissions at 1.08, 0.95, 0.81, and 0.62 eV are detected. The centers responsible for the emissions at 0.81 and 0.62 eV are tentatively attributed to Al-0-Ga and Al-O-Al, respectively, based on correlation with layer growth conditions. The growth parameters lead to information on the number of nearest-neighbor aluminum associated with oxygen. The Al-0-Ga center responsible for the 0.81 emission is also studied for Al,Gar,,As(x=0.05-0.9) layers grown by OMVPE without DMALMO. The 0.81 eV emission is attributed to the transition from the conduction band to the Al-0-Ga center. The center shows the lattice relaxation exemplified by the Franck-Condon shift of 0.15 eV. The thermal ionization energy of this acceptor is determined to be 0.56 eV above the valence band. 0 1995 American Institute of Physics.