Preparation and luminescence of blue-emitting phosphor Ca2PO4Cl:Eu2+ for n-UV white LEDs

Abstract A series of blue-emitting Ca 2 − x Eu x PO 4 Cl phosphors were synthesized by a solid state method in a reducing atmosphere. The factors those affect the structure and the photoluminescence (PL) intensities of phosphors, including the dosage of chlorine source CaCl 2 , reaction time and annealing temperature, have been investigated in detail. X-ray diffraction (XRD) and photoluminescence measurements were performed to testify the crystal structure and luminescent properties. The optimal Eu 2+ concentration was determined, and the mechanism of the concentration quenching was predominated by dipole–dipole interaction. The present phosphor exhibits a strong absorption in the near-UV region, emits an intense blue emission centered at 451 nm and presents excellent thermal stability, suggesting that the phosphor is competitive as a promising blue-emitting phosphor for near ultraviolet (n-UV) light-emitting diodes (LEDs).