Synthesis of Nitridosilicate CaSr[sub 1−x]Eu[sub x]Si[sub 5]N[sub 8] (x=0–1) Phosphor by Calcium Cyanamide Reduction for White Light-Emitting Diode Applications

A convenient calcium cyanamide reduction route was developed to synthesize the -doped nitridosilicate phosphors, , 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 was carried out in space group (no. 31) with pm, pm, and pm. The ions formed a complete solid solution by occupying the sites in host lattice. A typical sample doped with an optimized amount of (2 atom % vs ) showed a broadband absorption covering the range from UV to visible region and strong red emission peaking at , revealing that this phosphor was a potential candidate for the phosphor-converted white LEDs. Under excitation of , this phosphor gave the intensity comparable (about 120%) to that of yttrium aluminum garnet (P46-Y3) standard. The emission peaks of varied from 625 to with increasing ion concentration. The redshifting behavior of the emission band dominantly contributed to the energy migration among ions.