Abstract
Off-axis implantation of 80 keV Eu ions into epitaxial c-plane InAlN/GaN bilayers confines rare-earth (RE) doping largely to the InAlN layer. Rutherford backscattering spectrometry and x-ray diffraction show good correlations between the Eu3+ emission linewidth and key structural parameters of InxAl1-xN films on GaN in the composition range near lattice matching (x similar to 0.17). In contrast to GaN: Eu, selectively excited photoluminescence (PL) and PL excitation spectra reveal the presence of a single dominant optical center in InAlN. Eu3+ emission from In0.13Al0.87N: Eu also shows significantly less thermal quenching than GaN: Eu. InAlN films are therefore superior to GaN for RE optical doping. (C) 2009 American Institute of Physics. [doi:10.1063/1.3245386]