Lattice site location of optical centers in GaN: Eu light emitting diode material grown by organometallic vapor phase epitaxy

Eu-doped GaN was grown by organometallic vapor phase epitaxy at temperatures from 900 to 1100 degrees C. Eu incorporation is influenced by temperature with the highest concentration found for growth at 1000 degrees C. In all samples, Eu is incorporated entirely on substitutional Ga sites with a slight displacement which is highest (similar to 0.2 angstrom) in the sample grown at 900 degrees C and mainly directed along the c-axis. The major optical Eu3+ centers are identical for in situ doped and ion-implanted samples after high temperature and pressure annealing. The dominant Eu3+ luminescence lines are attributed to isolated, substitutional Eu. (c) 2010 American Institute of Physics. [doi:10.1063/1.3489103]