Molybdenophosphates Na2Y1-xEux(MoO4)(PO4) and Na2Y1-xTbx(MoO4)(PO4), were shown to exhibit photoluminescence (PL) properties for a broad substitution range. Under near-UV excitation, Na2Y(MoO4)(PO4):Eu3+ and Na2Y(MoO4)(PO4):Tb3+ phosphors show emission lines corresponding to D-5(0) -> F-7(J) (J = 0-4, red) and D-5(4) -> F-7(J) (J = 4-6, green), respectively. The critical concentrations of Eu3+ and Tb3+ are 0.5 and 0.7, respectively beyond which concentration quenching occurs. This behavior is explained on the basis of Eu3+-Eu3+ and Tb3+-Tb3+ distances. For x = 1, Na2Tb(MoO4)(PO4), emission from the D-5(4) level of Tb3+ that appears yellow in color is observed. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.071204jes] All rights reserved.