Luminescence Properties of High-Quality Ca_2Si_5N_8: Eu~(2+) Phosphor: CaH_2-Raw Material

摘要

Using cheaper CaH_2 as calcium sources and an efficient reductant, red emitting phosphors (Ca_(1-x)Eu_x)2Si_5N_8 (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 Eu~(2+)-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 Eu~(2+) 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 Li_3N concentration, the small particles gradually grow into well-crystallized and well-dispersed particles with a mean size of 5μm. The additive of Li_3N is helpful to improve the uniformity and coarsening of Ca_2Si_5N_8: Eu~(2+) particle.