A convenient calcium cyanamide (CaCN2) reduction route was developed to synthesize the Eu2+-doped nitridosilicate phosphors, CaSr1-xEuxSi5N8 (x = 0-1), and the photoluminescence properties of the obtained phosphors were characterized for solid-state lighting applications [white light-emitting diodes (LEDs)]. The Rietveld refinement analysis for undoped CaSrSi5N8 was carried out in space group Pmn2(1) (no. 31) with a = 569.0(4) pm, b = 673.0(1) pm, and c = 932.0(6) pm. The Eu2+ ions formed a complete solid solution by occupying the Sr2+ sites in CaSrSi5N8 host lattice. A typical sample doped with an optimized amount of Eu2+ (2 atom % vs Ca/Sr) showed a broadband absorption covering the range from UV to visible region (380-500 nm) and strong red emission peaking at 629 nm, revealing that this phosphor was a potential candidate for the phosphor-converted white LEDs. Under excitation of 460 nm, this phosphor gave the intensity comparable (about 120%) to that of yttrium aluminum garnet YAG:Ce3+ (P46-Y3) standard. The emission peaks of CaSr1-xEuxSi5N8: Eu2+ varied from 625 to 680 nm with increasing Eu2+ ion concentration. The redshifting behavior of the emission band dominantly contributed to the energy migration among Eu2+ ions. (c) 2007 The Electrochemical Society.