High-pressure and high-temperature annealing of diamond ion-implanted with various elements

We tried to dope various ions (B, Al, Ga, Mg, and Be) into diamond films by combining ion-implantation and high-pressure and high-temperature annealing. In cathodoluminescence spectra of Be-implanted films, previously unreported emissions appeared at 4.843, 4.687, 4.533 eV. These emissions were only observed from Be-implanted films, and they were not observed from B, Al, Ga, and Mg-implanted ones. The 4.843-eV line is assigned to zero phonon line, and the 4.687- and 4.533-eV lines are its phonon replicas because the energy difference between each peak is close to the optical phonon energy of diamond (~ 0.15 eV). The temperature dependence of the 4.843-eV line is similar to that of bound excitons.