Low-temperature (13 K) photoluminescence (PL) measurements of Mn+-ion-implanted GaN epilayers show distinctive features. For the thermally annealed GaN:Mn epilayers subsequent to the implantation of Mn+ ions, the typical (D-0, X) transition at 3.47 eV disappeared and two new strong excitonic transitions emerge at 3.31 and 3.37 eV. This is due to the fact that the incorporation of Mn+ forms cubic lattice structure and the interface between the cubic and wurzite phases is responsible for the new PL doublet structures. In addition, three more transitions believed to be associated with the Mn+ ions are resolved. Such results demonstrate the change of lattice structures due to the transformation from binary compound of GaN into ternary compound of GaN:Mn. (C) 2002 Elsevier Science B.V. All rights reserved.