Effect of annealing on metastable shallow acceptors in Mg-doped GaN layers grown on GaN substrates

Abstract

Mg-doped GaN layers grown by metal-organic vapor phase epitaxy on GaN substrates produced by the halide vapor phase technique demonstrate metastability of the near-band-gap photoluminescence (PL). The acceptor bound exciton (ABE) line possibly related to the C acceptor vanishes in as-grown samples within a few minutes under UV laser illumination. Annealing activates the more stable Mg acceptors and passivates C acceptors. Consequently, only the ABE line related to Mg is dominant in PL spectra for the annealed samples. The temporal changes in PL are permanent at low temperatures; however, they can be recovered after heating to 100 K or higher.Original publication: Pozina, G., Hemmingsson, C., Paskov, P.P., Bergman, J.P., Monemar, B., Kawashima, T., Amano, H., Akasaki, I. and Usui, A., Effect of annealing on metastable shallow acceptors in Mg-doped GaN layers grown on GaN substrates, 2008, Applied Physics Letters, (92), 15, 151904. http://dx.doi.org/10.1063/1.2909541. Copyright: American Institute of Physics, http://apl.aip.org/apl/top.js