The photoluminescence properties of a series of phosphors Ca(9)Ln(1-x)(PO4)(7):xTb(3+) (Ln(3+) = Y3+, La3+, Gd3+) (0.003 <= x <= 1) under the excitation of vacuum ultraviolet (VUV) light were investigated. The results indicate that the phosphors show tunable emitting colors depending on the concentrations of Tb3+. Among them, the samples Ca(9)Ln(0.4)(PO4)(7):0.6Tb(3+) (Ln(3+) = Y3+, La3+, Gd3+) exhibit strong green light emissions and a shorter luminescence decay time (tau(1/e) similar to 2.5 ms) than those of commercial green phosphor Zn2SiO4:Mn2+ (tau(1/e) > 5 ms), revealing that they can be potentially applicable as green phosphors for plasma display panels and Hg-free fluorescence lamps. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3526960] All rights reserved.