Achieving efficient violet-light-excited blue phosphors by nitridation for violet-chip-based full-spectrum lighting

With the pursuit of healthy lighting, full-spectrum white light-emitting diodes (WLEDs) fabricated with violet chips and tri-color phosphors have been put forward. However, the excitation bands of most reported blue phosphors are located in the ultraviolet (UV) region, which hinders the development of full-spectrum lighting. In this work, by partially introducing N3- into a matrix, a series of Ba0.697Al10.914O17.232-3y/2Ny:0.16Eu(2+) (BAON(y):Eu) blue phosphors with red-shifted photoluminescence excitation (PLE) spectra were synthesized. Under the excitation of 400 nm violet light, the internal/external quantum efficiency (IQE/EQE) values of the optimal sample BAON(1.0):Eu were calculated to be 80%/52%, while the retained integrated emission intensity at 150 degrees C can be 95% of that at room temperature. The WLED device fabricated by coating BAON(1.0):Eu and other commercial phosphors on a violet chip achieved an ultra-high color rendering index (R-a = 95.4). These results indicate that our synthesized BAON(1.0):Eu can be an excellent candidate blue phosphor for full-spectrum WLED lighting.