Corrugated organic light-emitting diodes to effectively extract internal modes

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Organic light-emitting diodes (OLEDs) suffer from limited light extraction efficiency.
• Surface plasmon polaritons (SPP) and waveguiding modes contribute to light loss within OLEDs.

Purpose of the Study:

• To develop and investigate a corrugated structure for enhanced light extraction in OLEDs.
• To optimize the corrugated structure for improved external quantum efficiency (EQE).

Main Methods:

• Fabrication of corrugated OLEDs using nano-imprinted blazed gratings with varying pitches.
• Experimental measurement and simulation of light extraction efficiency.
• Analysis of SPP and waveguiding mode extraction mechanisms for transverse electric (TE) and transverse magnetic (TM) waves.

Main Results:

• A 42.00% external quantum efficiency (EQE) enhancement was achieved with the internal corrugated structure.
• Attaching a macrolens further increased EQE enhancement to 103.02% by transferring modes into the substrate.
• Simulations confirmed the experimental findings and elucidated the extraction mechanism.

Conclusions:

• The corrugated structure effectively extracts SPP and waveguiding modes in OLEDs.
• This approach offers a cost-effective method to enhance optical efficiency for mass-produced OLED lighting and displays.
• The integration with a macrolens provides a significant boost in EQE.