Novel Color Converters for High Brightness Laser‐Driven Projection Display: Transparent Ceramics–Glass Ceramics Film Composite

Abstract

Laser‐driven projection display puts forward urgent demand for color converter materials to simultaneously achieve balanced‐spectrum properties and strong heat dissipation. Herein, this work develops a novel optofunctional composite by coupling Y3Al5O12:Ce3+ transparent ceramics (TC) with CaAlSiN3:Eu2+ phosphor‐in‐glass film (PiGF) for the first time. Remarkably, this new material architecture design enables a balance between the spectrum properties and heat dissipation ability, and can yield high‐quality white light with brightness of over 2500 lm, luminous efficacy (LE) of over 200 lm W−1, correlated color temperature (CCT) of 3700–4100 K, and improved color rendering index (CRI) of 60–70. Furthermore, the PiGF@TC‐converted laser projection system is also successfully designed, showing natural and real color restoration. Additionally, the combined action of thermal quenching and optical excitation intensity quenching is confirmed for the luminescence saturation upon high‐power blue laser driven. The main mechanism of optical quenching is identified to be energy upconversion dominated by second‐order nonlinear processes. The findings described here suggest a step toward developing the admirable laser‐driven color converters for next‐generation lighting sources.

Ce3+-Activated SrLu2Al3ScSiO12 Cyan-Green-Emitting Garnet-Structured Inorganic Phosphor Materials toward Application in Blue-Chip-Based Phosphor-Converted Solid-State White Lighting

“…Presently, the assembly of commercially available blue light InGaN LED chips and the yellow Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ) phosphor is the mainstream approach to fabricate warm white-light-emitting diodes (WLEDs). , However, the lack of a red component in the resulting spectrum of YAG:Ce 3+ causes the LED device to exhibit poor CRI, normally below 80, and high correlated color temperature, usually greater over 5000 K. , Although the addition of an additional commercial red-emitting CaAlSiN 3 :Eu 2+ phosphor in the above scheme is a simple and effective way to optimize Ra and CCT, it is impossible to obtain satisfactory Ra values (>95) due to the presence of a cyan gap in 480–520 nm region. , This pain point for the LED industry seriously hinders its further commercial application in photography, museums, art galleries, backlighting, and medical lighting. − In response to the issues mentioned above, two feasible approaches have been proposed by researchers to fabricate high-performance WLEDs toward a more comfortable illumination. One of the approaches is combining near-ultraviolet (near-UV) LED chips with tricolor phosphors (blue, green, and red). − Another option is employing the blue light chip to pump the mixed phosphors with red and green emission .…”

Highly efficient large-area ultrathin phosphor-glass composites fabricated by tape-casting for super-bright LED lights

“…However, such lighting devices usually suffer severe performance degradation as the mixture of phosphor and organic resin was heated up to a certain high-temperature by the self-heating of LED chip [8][9][10] . In recent years, traditional doped singlephase transparent ceramics and bulk crystals have emerged as e cient all-inorganic color converters, offering the potential to circumvent the need for organic encapsulation [11][12][13][14] . However, their costly preparation and limited variety have hindered scalable manufacture and widespread application.…”