New single-phase and near-ultraviolet (NUV)-excitable materials composed of Ba9EumMnY2Si6O24 (m = 0.01-0.5, n = 0-0.7) were prepared via a solid-state reaction in reducing atmosphere. X-ray diffraction patterns of the obtained phosphors were examined to index the peak positions. After doping the host structure with Eu2+ and Mn2+ emitters, the intense green, white, and orange emission lights that were observed in the photoluminescence spectra under NUV excitation were monitored. The dependence of the luminescent intensity of the Mn2+ co-doped (n = 0.1-0.7) host lattices on the fixed Eu2+ content (m = 0.1, 0.3, 0.5) is also investigated. Co-doping Mn2+ into the Eu2+-doped host structure enabled a high energy-transfer from Eu2+ to Mn2+ and their energy-transfer mechanism were discussed. Using these phosphors, the desired CIE values including emissions throughout the green to orange regions of the spectra were achieved. Efficient white-light light-emitting diodes (LEDs) were fabricated using Eu2+ and Mn2+ co-doped phosphors based on NUV-excitable LED lights. (C) 2013 Elsevier Ltd. All rights reserved.