Luminescence Properties of High-Quality Ca2Si5N8: Eu2+Phosphor: CaH2-Raw Material

Using cheaper CaH2 as calcium sources and an efficient reductant, red emitting phosphors (Ca1-xEux)2Si5N8 (x = 0.002, 0.005, 0.008, 0.01, 0.02 ∼ 0.09) were prepared under 1540°C via the traditional solid-state reaction method. The photoluminescence characteristics with various Eu2+-doping concentrations were investigated. A broad excitation spectrum is full with a range of 200∼600 nm. Broad band emissions and a high absorption were achieved and the emission peaks shifted from 603 to 617 nm with increased Eu2+ concentration. A large emission tunability and a high solubility of activators (a 14 nm red-shift at x = 0.09) make the obtained phosphors excellent candidates for LED conversion phosphors. With increasing Li3N concentration, the small particles gradually grow into well-crystallized and well-dispersed particles with a mean size of 5 μm. The additive of Li3N is helpful to improve the uniformity and coarsening of Ca2Si5N8: Eu2+ particle.