Homoepitaxial growth of GaN under Ga-stable and N-stable conditions by plasma-assisted molecular beam epitaxy - Tarsa, E. J.; Heying, B.; Wu, X. H.; Fini, P.; DenBaars, S. P.; Speck, J. S. (American Institute of Physics (AIP), 1997)
http://dx.doi.org/10.1063/1.365575
Keywords: U