GaN doped with neodymium by plasma-assisted molecular beam epitaxy

Abstract

We report in situ doping of GaN with the rare earth element Nd by plasma-assisted molecular beam epitaxy. For the highest Nd effusion cell temperatures, Rutherford backscattering and secondary ion mass spectroscopy data indicate ∼5 at. % Nd in epilayers grown on c -plane sapphire. X-ray diffraction found no evidence of phase segregation under nitrogen-rich conditions with up to ∼1 at. % Nd, with the highest luminescence intensities corresponding to doping of ∼0.5 at. %. Spectral correlation of the Nd emission multiplets for above (325 nm) and below (836 nm) GaN bandgap excitations implies enhanced substitutional doping at the Ga site. © 2008 American Institute of Physics.