Characterization of AlN:Mn thin film phosphors prepared by metalorganic chemical vapor deposition

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 (0 0 0 1) wafers by an atmospheric-pressure metalorganic chemical vapor deposition at 1050 °C. The grown films were polycrystal oriented preferentially towards the 〈0001〉 direction of wurtzite structure. It is suggested from the dependence of Mn concentration (CMn)(CMn) on the lattice constant and the low-temperature photoluminescence spectrum that most of the Mn atoms occupy the lattice sites for CMnCMn up to about 1×1020cm-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/m2, has been obtained from the layer with CMnCMn of 3×1019cm-3 under the excitation conditions of 5 kV and 0.1 mA/cm2 as an accelerating voltage and a current density, respectively.