Lattice Location and Luminescence Behavior of Rare Earth Elements Implanted in GaN

Single crystalline GaN-layers were implanted with radioactive 167 Tm and 169 yb ions, and their lattice sites were determined using the emission channeling technique. After the decay of 167 Tm to 167 Er, photoluminescence studies were performed. Upon room temperature implantation, rare earth atoms immediately occupy relaxed substitutional sites with an average relaxation of about 0.025 nm. Isochronal annealing treatments up to 800 °C and co-implantation of oxygen to a dose an order of magnitude greater than that of the Tm or Yb do not influence the rare earth lattice sites. A variety of different rare earth related luminescence lines are observed, and co-implantation of oxygen strongly changes the line intensities.