A comparative study of photo-, cathodo- and ionoluminescence of GaN nanowires implanted with rare earth ions

GaN nanowires (NWs) implanted with Europium, Praseodymium and Erbium ions were analysed by Pho- toluminescence (PL), Cathodoluminescence (CL) and Ionoluminescence (IL). The red 5 D0 ? 7 F2 and 3 P0 ? 3 F2 luminescence of the Eu transitions were identified in the visible and infra-red spectral range. Besides the lanthanide luminescence, the heat treated GaN NWs exhibit the band edge recombination and a deep level emission in the yellow spectral range when the samples are excited by photons, elec- trons and protons with energies of 3.8 eV, 5.0 keV and 2.0 MeV, respectively. At RT, the dependence of GaN NW luminescence intensity with the illumination/irradiation time was analysed using PL, CL and IL. The effects of the different excitation mechanisms are discussed to explain the observation that the broad emission bands suffer a luminescence quenching for the GaN NWs irradiated with energetic par- ticles and photons. The influence of the irradiation on the optical properties of the GaN NWs is discussed and models for the recombination processes are established.