Luminescence of emission-tunable Na15.6Ca3.84Si12O36:Ce3+,Tb3+,Na+ phosphors for near-ultraviolet light-emitting diodes

Abstract A series of Na 15.6 Ca 3.84 Si 12 O 36 :Ce 3+ ,Tb 3+ ,Na + (NCS:Ce 3+ ,Tb 3+ ,Na + ) phosphors were prepared by conventional solid-state reaction method, and their photoluminescence properties under near-ultraviolet (NUV) excitation were studied. The excitation spectrum of Ce 3+ -single-doped NCS showed a broad excitation band from 250 to 400 nm, which could well match with the emission wavelength of the NUV LED chip. Upon 365 nm excitation, the NCS:Ce 3+ ,Na + phosphor demonstrated a blue emission in the range of 400–600 nm with the predominated peak at 443 nm. By co-doping Tb 3+ into NCS:0.04Ce 3+ ,0.04Na + , tunable-emission was realized due to the energy transfer from Ce 3+ to Tb 3+ , and nearly white light was also obtained. The investigation also revealed that warm white light could be further generated by combining the NCS:0.04Ce 3+ , y Tb 3+ ,(0.04+ y )Na + with other red-emitting phosphors. Thus, the NCS:Ce 3+ ,Tb 3+ ,Na + phosphors could be promising candidate for white LEDs.