Color-tunable blue-emitting Na2MgSiO4:Ce3+ phosphors for white light-emitting diodes

Phosphor-converted white light-emitting diodes (pc-wLEDs) based on near-UV LED chip demand efficient blue-emitting phosphors, because the pc-wLED uses either multi phosphors or single-phase white-emitting phosphor both needs blue-emitting component. When using Ce3+ as the activator, the host structure usually has rare earth ions or alkaline earth ion such as Ca2+ for Ce3+ to occupy, due to similar ionic radius and charge. This work is going to report a blue-emitting phosphor Na2MgSiO4:Ce3+, where Ce3+ occupies the Na+ sites. The phosphor exhibits characteristic of tunable emission color upon increasing Ce3+ content or introducing Li+ as charge compensator. The relationship between the crystal structure and the luminescent properties was studied in detail based on structural refinement and in-depth luminescent studies. The phosphor with a proper Ce3+ content showed a high absolute quantum efficiency of 86.0% and acceptable thermal stability. The pc-wLED made of 365 nm UV chip, the as-prepared Na2MgSiO4:Ce3+,Li+, and commercial green and red phosphors showed good performance with color rendering index of 93.3.