Luminescence material characterizations on laser-phosphor lighting techniques.

Area of Science:

• Optoelectronics
• Materials Science
• Solid-state Lighting

Background:

• Laser-phosphor technology offers efficient lighting solutions.
• Material selection is critical for managing thermal effects and performance.
• Understanding heat spreading in phosphor materials is key for high-power applications.

Purpose of the Study:

• To characterize laser-phosphor lighting using three carrier types: phosphors in silicone (PiS), phosphors in glass (PiG), and ceramic binders (CP).
• To investigate the impact of thermal management on phosphor luminescence and laser power operation.
• To correlate material thermal conductivity with maximum laser power handling.

Main Methods:

• Experimental characterization of PiS, PiG, and CP materials in a laser projector light source module.
• Measurement of conversion efficiency and maximum laser power operation for each material.
• Thermal conductivity assessment and correlation with operational performance.
• Finite element analysis (FEA) to simulate heat spreading and thermal resistance.

Main Results:

• Conversion efficiencies: PiS (29.7%), PiG (34.6%), CP (31.8%).
• Maximum laser power operations: PiS (3.9 W), PiG (7.9 W), CP (17.2 W).
• Ceramic binders (CP) showed superior thermal conductivity (17.0 W/m·K), enabling higher laser power operation and reduced hot-spot effects.
• A CP device achieved 50.2 W maximum laser operation with temperatures below 100 °C.
• Simulations indicated CP's low sensitivity to heat transfer coefficient variations.

Conclusions:

• Ceramic binders (CP) are a promising material for high-power laser-phosphor applications due to excellent thermal management.
• Material thermal conductivity is a critical factor for achieving high laser power operation in laser-phosphor systems.
• The developed CP device demonstrates efficient and stable performance at high power levels.