Lattice distortions and transmuted-Ge related luminescence in neutron transmutation doped material were studied by using Rutherford back-scattering spectroscopy channelling, Raman scattering and photoluminescence methods. A lattice displacement of Ga atoms, by about 0.012nm from the <00•1> row, was estimated from the normalized angular yield profiles, preserving monocrystallinity in as-irradiated material with a minimum yield of 7%. A 2.84eV emission band, observed in 600C-annealed neutron transmutation doped samples was associated with the Ga interstitial supporting the lattice distortion. Two emission bands (at 2.90 and 2.25eV), observed in 1000C-annealed neutron transmutation doped material, were attributed to a negatively charged DX-like center of Ge at a Ga site, and to a complex defect which was attributed to Ge at a Ga site and Ga vacancy, respectively.

Lattice Distortions and the Transmuted-Ge Related Luminescence in Neutron-Transmutation-Doped GaN. K.Kuriyama, T.Tokumasu, J.Takahashi, H.Kondo, M.Okada: Applied Physics Letters, 2002, 80[18], 3328-30