Realizing High-Brightness and Ultra-wide Color Gamut Laser-Driven Backlighting by Using Laminated Phosphor-in-Glass (PiG) Films

As a new generation advanced display or projection technology, laser displays or projectors has attracted great attentions owing to their ultra-high brightness, energy saving, brilliant images and/or large sizes. However, for laser displays or projectors without using three primary laser diodes, the lack of appropriate blue-laser-driven color converters is a big bottleneck and challenge. In this work, we propose to develop laminated phosphor-in-glass (PiG) films as laser-driven color converters for wide-color-gamut and high brightness laser displays. β-Sialon:Eu and Calson:Ce phosphors were respectively chosen as the green and orange emitters, and were co-fired with glass frits on a sapphire substrate to form PiG films. No interfacial reactions between phosphors and glass were identified, and phosphor powders were uniformed distributed in the glass matrix. The phosphor content and film thickness impacted an influence in the microstructure, luminance saturation and optical properties of PiG films under laser light irradiations, both PiG films reached a maximum luminance saturation of 6.09 Wmm-2 when their microstructures were optimized. The lamination architecture of PiG films had a great impact on the optical properties of laser-driven white light, and the maximum ones were achieved as the green-emitting PiG film was positioned on the orange-emitting film adhered to the sapphire substrate. Under 4.82 Wmm-2 blue laser excitation, the laminated double-layer PiG films enabled to create white light with a wide color gamut of 107% NTSC, luminous efficacy of 74.44 lmW-1, luminous flux of 282.13 lm and a color temperature of 7902 K. These results indicate that the laminated PiG films are promising color converters for use in high-power and wide color gamut laser displays or projectors