The structural and luminescent properties of AlN:Mn films, which showed red-orange luminescence originated from the transition of 3d-electrons in a Mn ion, were investigated. The samples were grown on sapphire (0001) wafers by an atmospheric-pressure metalorganic chemical vapor deposition at 1050 degrees C. The grown films were polycrystal oriented preferentially towards the < 0001 > direction of wurtzite structure. It is suggested from the dependence of Mn concentration (C-Mn) on the lattice constant and the low-temperature photoluminescence spectrum that most of the Mn atoms occupy the lattice sites for C-Mn up to about 1 x 10(20) cm(-3). The samples exhibited bright cathodoluminescence reflecting the improved crystalline quality compared to that of the low-temperature-grown samples. The highest luminance, 245 cd/m(2), has been obtained from the layer with C-Mn of 3 x 10(19) cm(-3) under the excitation conditions of 5 kV and 0.1 mA/cm(2) as an accelerating voltage and a current density, respectively. (c) 2006 Elsevier B.V. All rights reserved.