High performance narrow-band green-emitting phosphors for white LEDs: recent advances and perspectives

Abstract

Ultra-wide color gamut backlight is the key to achieve ultra-high definition and ultra-high resolution liquid crystal display (LCD), in which green-emitting phospohrs with narrow spectral emission are the decisive factors. However,the key green-emitting phosphors currently used for light emitting diode (LED) backlights, shch as commercial β-SiAlON:Eu2+, has the disadvantages of wide emission band and large particles. In order to display more colorful and vivid photograph, it’s urgent to accelerate the development of narrow-band green-emitting phospohr with independent intellectual property rights and high quantum efficiency. This article outlines the design of green-emitting phosphors and the improvement of their luminescent properties. From design aspect, an excellent phosphor should consider host and activator. The emission band of Tb3+, Mn2+, Ce3+ and Eu2+ usually located in the visible region, and the short luminesce decay time of Eu2+/Ce3+ makes Eu2+/Ce3+ as the potential activator for high-quality display. For selecting the host, single particle diagnosis approach, high-throughput density functional theory (DFT) calculation and mineral-inspired prototype evolution are used to explore novel phosphors. The thermal stability and quantum efficiency (QE) are the important properties and their enhancing strategies are presented. Moreover, the color gamut of many green-emitting phosphors is shown and the green-emitting phosphor-based WLEDs are used in LCD screen and projector, which shows more vivid pictures than commercial WLED. Finally, the future outlook of how to explore green-emitting phosphors with better perfomance was discussed.