Impurity-Related Luminescence of Homoepitaxial GaN Studied with High Magnetic Fields

Recent magnetoluminescence results obtained for homoepitaxial GaN layers are presented. The neutral impurity-bound excitons and donor–acceptor pair emission lines have been studied in magnetic fields up to 27 T. Low-temperature luminescence spectra have been measured with the magnetic field parallel and perpendicular to the hexagonal c-axis of the GaN layers. Experimental results allowed us to evaluate diamagnetic shifts, effective g-factors of electrons and holes involved in neutral donor and neutral acceptor complexes as well as the electron–hole exchange constant for close donor–acceptor pairs. Both the fine structure of the neutral acceptor-bound exciton emission and the specific properties of donor–acceptor pair spectra observed in magnetoluminescence experiments are tentatively attributed to the internal structure of the acceptor state.