Photoluminescence Enhancement of Ca5(Po4)2sio4:Sm3+ Orange Phosphor Through Charge Compensation of A+ (a = Li, Na and K) Ions for White Light-Emitting Diodes

The orange-emitting Ca5-x(PO4)2SiO4:xSm3+ (C5PSO:Sm3+) phosphor was prepared via a simple solid-state method, and the charge compensators A+ (A = Li, Na and K) was codoped into C5PSO:Sm3+ for improving the luminescence performance. The influences of Sm3+/A+ codoping as well as Sm3+ doping on the crystal structure and luminescence performance of C5PSO:Sm3+ phosphor were investigated in detail. The X-ray diffraction results exhibited that all as-prepared samples were assigned to the standard structure Ca5(PO4)2SiO4 possessing P63/m space group. Under near-ultraviolet excitation of 401 nm, the characteristic emission peaks of C5PSO:Sm3+ phosphors are located at 558 nm, 605 nm and 656 nm respectively, which deriving from the 4G5/2→6HJ (J = 5/2, 7/2, 9/2) electron transitions of Sm3+ ions. Furthermore, the significant luminescence improvement of C5PSO:Sm3+ phosphor was attained through charge compensation of codoped A+ ions, and the emission intensity is enhanced by 2.92-, 2.62-, and 1.80-fold for K+, Na+, and Li+, respectively. Additionally, the actual orange-red LED and w-LED fabricated with as-prepared C5PSO:Sm3+, K+ phosphor showed an excellent optical performance. All results demonstrated that C5PSO:Sm3+, K+ orange-emitting phosphor could act as a potential red component in the w-LEDs illumination field.