A highly efficient narrow-band blue phosphor of Bi3+-activated cubic borate Ba3Lu2B6O15 towards backlight display applications

Developing innovative efficient phosphors featured with a narrow-band emission is essential for present white light-emitting diodes (wLEDs) towards high-performance liquid-crystal display (LCD) backlights applications, especially for Bi3+-activated phosphors. Herein, we synthesized a near-ultraviolet (n-UV) excitable narrow-band blue-emitting Ba3Lu2B6O15:Bi3+ (BLB:Bi3+) phosphor. It exhibits a narrow band emission (full-width at half maximum, FWHM = 35.5 nm), high color purity of 97.76%, surprisingly high internal quantum efficiency (IQE) which reached up to 90.6%, excellent thermal stability (85%@150 degrees C of the integrated emission intensity at room temperature) and reversibility and high consistency. The outstanding photoluminescence properties of Bi3+ are attributed to a highly symmetrical crystal field environment and tightly connected polyhedral network of Ba3Lu2B6O15. In addition, the energy level scheme is constructed from the calculated electronic structure to explore the difference in luminescence stability of Ce and Bi doped BLB phosphors. The pc-wLED device fabricated using commercial green beta-Sialon:Eu2+, red K2SiF6:Mn4+, and as-prepared blue BLB:Bi3+ phosphor on a 365 nm n-UV chip covered 90.06% of the color space of National Television System Committee (NTSC) standard, suggesting great potential for industrial applications as LCD backlighting.

Automated summary

Developing innovative and efficient phosphors with narrow-band emission is crucial for improving the performance of white light-emitting diodes in liquid-crystal display backlight applications. In this study, a near-ultraviolet excitable narrow-band blue-emitting Ba3Lu2B6O15:Bi3+ phosphor was successfully synthesized, demonstrating outstanding photoluminescence properties.