Zirconia/phenylsiloxane nano-composite for LED encapsulation with high and stable light extraction efficiency

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• LED encapsulation is crucial for light extraction efficiency (LEE) and device stability.
• Current encapsulation methods often lack rapid processibility and long-term stability.
• Developing advanced encapsulants with tailored optical properties is essential for high-performance LEDs.

Purpose of the Study:

• To develop a rapid processible, UV curable nano-composite encapsulant for LEDs.
• To enhance light extraction efficiency (LEE) and stability of LED devices.
• To optimize the composition of zirconium dioxide (ZrO2)/phenyl-siloxane nano-composites (ZSC) for superior optical performance.

Main Methods:

• Synthesis of highly crystalline ZrO2 nanoparticles (∼14 nm) via a modified hydrothermal method.
• Synthesis of UV curable methacryl-diphenyl-polysiloxane (MDPS) with a refractive index of 1.54.
• Preparation and optimization of ZSC double-layer encapsulants with varying ZrO2 content (0-20 wt%).

Main Results:

• Achieved high refractive indexes (RIs) ranging from 1.54 to 1.61 in ZSC composites.
• The double-layer encapsulated sample (M-10/M) demonstrated significantly higher LEE (11.2% before, 64.8% after sulfur vapor erosion) compared to commercial encapsulants.
• Maintained LED color temperature variation below 1% and reduced UV curing time to 1/6th of thermal curing.

Conclusions:

• UV curable ZSC double-layer encapsulants offer a rapid and effective solution for enhancing LED LEE and stability.
• The optimized ZrO2 content in the nano-composite is critical for maximizing optical performance.
• This approach provides a promising pathway for next-generation, high-efficiency LED packaging.