Composites based on Eu²⁺-activated LiSr₄(BO₃)₃ as broadband red components for LEDs

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photonic Materials

Background:

• White light-emitting diodes (WLEDs) require high-quality red light components for superior color rendering.
• Thermally stable phosphors are crucial for maintaining WLED performance and longevity.

Purpose of the Study:

• To synthesize and characterize Eu²⁺-doped LiSr₄(BO₃)₃ (LSBO) phosphor.
• To investigate the thermal and optical stability of LSBO phosphor in polymer composites for WLED applications.

Main Methods:

• Solid-state reaction synthesis of LSBO:Eu²⁺ phosphor.
• Incorporation of phosphor into silicone, polyurethane, and epoxy matrices.
• Long-term thermal aging (10,000 hours at 100°C) and temperature-dependent photoluminescence measurements (-40°C to 150°C).

Main Results:

• LSBO:Eu²⁺ exhibits broad red emission centered at ~640 nm.
• Silicone-based composites demonstrated superior optical durability and thermal resilience compared to polyurethane and epoxy.
• Optimized silicone composites maintained spectral shape and intensity under thermal stress.

Conclusions:

• Eu²⁺-doped LSBO phosphor is a promising red-emitting material for WLEDs.
• Silicone-based polymer-phosphor composites offer excellent spectral stability and thermal robustness.
• This work presents a viable path for advanced red compensation in next-generation WLEDs.