Strategy to Construct High Thermal-Stability Narrow-Band Green-Emitting Si-CDs@MAs Phosphor for Wide-Color-Gamut Backlight Displays

Developing innovative narrow-band green-emitting phosphors featuring low thermal quenching and eco-friendliness for white light-emitting diode (WLED) backlights is a pivotal challenge. Benefitting from narrowband and low toxicity of green-emitting silanized carbon dots (Si-CDs), an efficient confinement and protection strategy through embedding Si-CDs in mesoporous aluminas (MAs) is proposed to construct MAs and Si-CDs composites (Si-CDs@MAs) with superior luminescence properties. Si-CDs@MAs phosphor exhibits green emission at 526 nm with narrow full width at half maximum of 51 nm, zero-thermal quenching even up to 423 K (104.1%@423 K of the emission peak intensity at 298 K), and the internal quantum efficiency of 64.46%. Compared with broad-band yellow-emitting solid-state Si-CDs (S-Si-CDs), the thermal stability, photostability, and water stability of Si-CDs@MAs phosphor are remarkably improved due to surface protection. The WLED backlight is fabricated with optimized Si-CDs@MAs phosphor, which shows high luminous efficacy of 117.43 lm W-1 and wide color gamut (107% NTSC). Furthermore, this work provides the design principles of realizing stable narrow-band solid-state fluorescence carbon dots, suggesting its great potential for wide-color-gamut display application.

Automated summary

This study proposes a strategy to develop composite materials with excellent luminescent properties by using silanized carbon dots and mesoporous aluminas. The composite material exhibits narrow-band green emission, low thermal quenching, and high thermal stability. By optimizing the composite material for WLED backlight, high luminous efficacy and wide color gamut are achieved.