Transparent Ceramic@Sapphire Composites for High-Power Laser-Driven Lighting.

Area of Science:

• Materials Science
• Solid-State Lighting
• Optoelectronics

Background:

• Phosphor ceramics are promising for high-power laser lighting but suffer from luminance saturation.
• Conventional methods using microcrystalline grains have limitations in thermal conductivity and luminescence dilution.

Purpose of the Study:

• To develop a novel transparent ceramic@sapphire composite material to overcome luminance saturation in phosphor ceramics.
• To enhance thermal conductivity and luminescence performance for high-power laser lighting applications.

Main Methods:

• Fabrication of ceramic@sapphire composites via high-temperature sintering.
• Characterization of thermal conductivity and luminescence properties.
• Evaluation of composite performance using Lu2-xCaxMg2Si3O12: xCe3+@sapphire as a model system.

Main Results:

• The ceramic@sapphire composite achieved a thermal conductivity of 36.9 W·m⁻¹K⁻¹.
• Luminescence improvements ranged from 152-319%, and luminance saturation thresholds increased by 100-233%.
• The optimized composite demonstrated a luminous flux of 5902 lm and luminous efficacy of 148 lm W⁻¹.

Conclusions:

• The novel ceramic@sapphire composite design effectively enhances thermal conductivity and luminescence performance, overcoming saturation effects.
• This strategy is versatile across different ceramic systems and offers a scalable approach for next-generation solid-state lighting.
• Practical applications, such as automotive headlights, show potential for higher luminance intensity and extended illumination distances.