Published online by Cambridge University Press: 17 March 2011
In this work we report the structural and optical properties of ionimplanted GaN. Potential acceptors such as Ca and Er were used as dopants.Ion implantation was carried out with the substrate at room temperature and550 °C, respectively. The lattice site location of the dopants was studiedby Rutherford backscattering/channeling combined with particle induced X-rayemission. Angular scans along both [0001] and [1011] directions show that50% of the Er ions implanted at 550 °C occupy substitutional or nearsubstitutional Ga sites after annealing. For Ca we found only a fraction of30% located in displaced Ga sites along the [0001] direction. The opticalproperties of the ion implanted GaN films have been studied byphotoluminescence measurements. Er- related luminescence near 1.54 µm isobserved under below band gap excitation at liquid helium temperature. Thespectra of the annealed samples consist of multiline structures with thesharpest lines found in GaN until now. The green and red emissions were alsoobserved in the Er doped samples after annealing.