Photoluminescence of GaN : Mg grown by metalorganic vapor-phase epitaxy (MOVPE)

We report on the luminescence properties of Mg-doped GaN grown by metalorga nic vapor-phase epitaxy (MOVPE). Samples with various Mg concentrations and differing degrees of activation were investigated. From the donor-acceptor pair (DAP) line position an ionization energy of the acceptor of 173 meV w as concluded. A further recombination line dominated by the low energy shou lder of the first phonon line of the DAP was found, its origin still being under investigation. Further experimental evidence is presented regarding t he deep donor related nature of the blue luminescence line at 2.9eV. The ba nd gap narrowing at high Mg concentrations was measured to be of the order of 10 meV. (C) 1999 Elsevier Science B.V. All rights reserved.