Photoluminescence enhancement of orange-emitting Ca(PO)SiO:Sm phosphor through charge compensation of A (Li, Na and K) ions for white light-emitting diodes.

The orange-emitting Ca(PO)SiO:Sm (CPSO:Sm) phosphor was prepared a simple solid-state method, and the charge compensators A (A = Li, Na and K) were codoped into CPSO:Sm for improving the luminescence performance. The influences of Sm doping and Sm/A codoping on the crystal structure and the luminescence performance of the CPSO:Sm phosphor were investigated in detail. The X-ray diffraction results exhibited that all the as-prepared samples were assigned to the standard structure Ca(PO)SiO possessing the 63/ space group. Upon near-ultraviolet excitation at 401 nm, the characteristic emission peaks of the CPSO:Sm phosphors are located at 558 nm, 605 nm and 656 nm, respectively, which are derived from the G → H ( = 5/2, 7/2, and 9/2) electron transitions of Sm ions. Furthermore, a significant luminescence improvement of the CPSO:Sm phosphor was attained through charge compensation of codoped A ions, and the emission intensity is enhanced by 1.79-, 1.45-, and 1.14-fold for K, Na, and Li, respectively. In addition, the actual orange-red LED and w-LED fabricated with the as-prepared CPSO:Sm,K phosphor showed excellent optical performance. All the results demonstrated that the CPSO:Sm,K orange-emitting phosphor could act as a potential orange-red component in the w-LEDs illumination field.