Plasmonic Enhancement and Angular Control of Narrow-Emitting Europium-Based Luminescence

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Europium-based emitters provide narrow-band red luminescence suitable for OLEDs.
• Their long excited-state lifetimes hinder device efficiency compared to alternative materials.

Purpose of the Study:

• To demonstrate how plasmonic resonances can reduce excited-state lifetime.
• To enable directional emission outcoupling for luminescent materials.
• To improve efficiency of Eu-based emitters.

Main Methods:

• Fabrication of one-dimensional aluminum plasmonic crystals (PCs).
• Control of photoluminescence directionality in Eu(dbm)3(TDZP) using tailored PC periodicity.
• Achieving spectral overlap between surface plasmon resonances and europium's electric dipole transition at 612 nm.

Main Results:

• Tuning PC periodicity directed emission to near ±7° with a 5° angular divergence.
• Observed a 4-fold enhancement in photoluminescence intensity at resonance.
• Decreased the excited-state lifetime of Eu(dbm)3(TDZP) by 1.7 times through plasmon coupling and outcoupling.

Conclusions:

• Plasmonic engineering effectively controls emission directionality and enhances photoluminescence.
• Integrating plasmonic resonances reduces excited-state lifetime, overcoming a key limitation of lanthanide emitters.
• Demonstrated potential for plasmonic crystals to improve OLED efficiency using Eu-based materials.