Photoluminescence of erbium-implanted GaN and in situ-doped GaN:Er

The photoluminescence of in situ-doped GaN:Er during hydride vapor phase epitaxy was compared to an Er-implanted GaN sample. At 11 K, the main emission wavelength of the in situ-doped sample is shifted to shorter wavelengths by 2.5 nm and the lifetime is 2.1±0.1 ms as compared to 2.9±0.1 ms obtained for the implanted sample. The 295 K band edge luminescence of the in situ-doped sample was free of the broad band luminescence centered at 500 nm which dominated the spectrum of the implanted sample. Reversible changes in the emission intensity of the in situ-doped sample upon annealing in a ${\mathrm{N}}_{\mathrm{2}}$ versus a ${\mathrm{NH}}_{\mathrm{3}}/{\mathrm{H}}_{\mathrm{2}}$ ambient indicate the probable role of hydrogen in determining the luminescence efficiency of these samples.