Surface lattice resonances for beaming and outcoupling green LEDs emission

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Light-Emitting Diodes (LEDs) typically have Lambertian emission, requiring secondary optics for application-specific light control.
• Tailoring LED emission is crucial for optimizing performance in various applications.

Purpose of the Study:

• To introduce plasmonic metasurfaces to InGaN quantum wells for LEDs.
• To control far-field emission directionality and enhance light collection efficiency.

Main Methods:

• Utilized surface lattice resonances (SLRs) via near-field coupling between InGaN multiple quantum wells (MQWs) and aluminum (Al) nanodisk arrays.
• Employed Fourier microscopy to analyze angular photoluminescence emission patterns.
• Performed numerical calculations based on the reciprocity principle.

Main Results:

• Demonstrated that the angular photoluminescence emission pattern is tunable by the metasurface lattice constant.
• Achieved a 5x enhancement in collected outcoupled light intensity by integrating Al metasurfaces.
• Numerical calculations showed excellent agreement with experimental data.

Conclusions:

• Plasmonic metasurfaces effectively control LED emission directionality without secondary optics.
• The approach avoids post-etching of GaN, offering a viable method for enhancing light generation in micro-LEDs.