Highly Reflective Thin-Film Optimization for Full-Angle Micro-LEDs

Area of Science:

• Optoelectronics
• Materials Science
• Display Technology

Background:

• Micro-light-emitting diodes (micro-LEDs) are promising for next-generation displays due to high contrast, brightness, and color purity.
• Traditional optical lenses struggle to optimize light distribution for the small light source area of micro-LEDs, limiting applications.
• Achieving uniform, wide-angle light emission is crucial for advanced display modules.

Purpose of the Study:

• To develop and demonstrate a primary optical design for micro-LEDs using dielectric and metal thin-film coatings.
• To optimize light distribution and achieve full-angle utilization for micro-LED displays.
• To overcome the limitations of traditional lenses in micro-LED light field adjustment.

Main Methods:

• Designed highly reflective thin-film coatings (dielectric and metal) with low absorption for micro-LED surfaces.
• Applied these coatings to micro-LED prototypes to modify light distribution.
• Evaluated optical performance, including light distribution width and center intensity, under low voltage and low loss conditions.

Main Results:

• The thin-film coating effectively optimized light distribution for micro-LEDs.
• The full width at half maximum (FWHM) of the light distribution was enhanced to 165°.
• Center intensity was reduced to 63% of the original value, indicating a broader, more uniform light spread.

Conclusions:

• A full-angle micro-LED with a highly reflective thin-film coating was successfully realized.
• This technology offers advantages for commercial advertising displays and plane light source modules requiring wide viewing angles.
• The developed thin-film coating enhances micro-LED performance for broad application.