Thermal annealing of GaN implanted with Be

GaN samples were implanted with Be and annealed in different conditions in order to activate the shallow Be-Ga acceptor. Low-temperature photoluminescence spectra were studied to find Be-Ga-related defects in the implanted samples. A yellow band with a maximum at about 2.2 eV (the YLBe band) was observed in nearly all samples protected with an AlN cap during the annealing and in samples annealed under ultrahigh N-2 pressure. A green band with a maximum at 2.35 eV (the GL2 band), attributed to the nitrogen vacancy, was the dominant defect-related luminescence band in GaN samples annealed without a protective AlN layer. The ultraviolet luminescence (UVLBe) band with a maximum at 3.38 eV attributed to the shallow Be-Ga acceptor with the ionization energy of 0.113 eV appeared in implanted samples only after annealing at high temperatures and ultrahigh N-2 pressure. This is the first observation of the UVLBe band in Be-implanted GaN, indicating successful activation of the Be-Ga acceptor. Published under an exclusive license by AIP Publishing.

Automated summary

Investigation of Be-implanted GaN samples subjected to annealing under different conditions revealed the activation of shallow Be-Ga acceptor and the presence of Be-Ga-related defects, as analyzed by low-temperature photoluminescence spectra.