A red-emitting phosphor Sr-5(BO3)(3)Cl:Eu2+ was systematically investigated by means of X-ray powder diffraction, diffuse reflection spectra, photoluminescence excitation and emission spectra, a concentration quenching process, and a thermal quenching process with the aim to enlarge the fundamental knowledge about the luminescence of Eu2+ in Sr-5(BO3)(3)Cl host lattice. (C) 2008 The Electrochemical Society. [DOI: 10.1149/1.2992707] All rights reserved.