Raman Scattering and Photoluminescence in Ge-implanted GaN Films

The investigations on Ge-implanted GaN films grown by MOCVD and then annealed at 1100℃ under ammonia ambient have been carried out. With increasing Ge implantation dose, four additional peaks arise at wave numbers of 260, 314, 428 and 670cm-1 in Ramam spectra. In PL spectra, the relative intensity of the band-edge emission compared to the PL-band centered at 2.66eV and the yellow band decreases with increase of Ge-implanted dose. The modes of 260 and 314cm-1 are attributed to disorder-activated Raman scattering, whereas the modes of 428 and 670cm-1 are assigned to local vibrations of vacancies and vacancy-related complexes. The PL-band centered at 2.66eV and the yellow band is also related to these vacancy defects. The new Raman peak at 301cm-1 for the sample annealed only 5min originates from Ge clusters due to deficient annealing.

Raman Scattering and Photoluminescence in Ge-implanted GaN Films

The investigations on Ge-implanted GaN films grown by MOCVD and then annealed at 1 100 ℃ under ammonia ambient have been carried out. With increasing Ge implantation dose, four additional peaks arise at wave numbers of 260, 314, 428 and 670 cm-1in Ramam spectra. In PL spectra, the relative intensity of the band-edge emission compared to the PL-band centered at 2.66 eV and the yellow band decreases with increase of Ge-implanted dose. The modes of 260 and 314 cm-1are attributed to disorder-activated Raman scattering, whereas the modes of 428 and 670 cm-1are assigned to local vibrations of vacancies and vacancy-related complexes. The PL-band centered at 2.66 eV and the yellow band is also related to these vacancy defects. The new Raman peak at 301 cm-1for the sample annealed only 5 min originates from Ge clusters due to deficient annealing.