Harnessing Metallic Nanoparticle-Based Anodes for Red-Shifting and Reshaping Electroluminescence toward the
Nurul Ridho Al Amin1, Ming-Jun Lin1, Jui-Ming Wang1
1Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan.
ACS Applied Materials & Interfaces
|July 7, 2025
Summary
This study developed high-performance, color-tunable near-infrared organic light-emitting diodes (OLEDs) using silver nanoparticles and titanium dioxide coatings. This localized surface plasmon resonance (LSPR) approach extends red emitter wavelengths without needing dedicated NIR emitters.
Area of Science:
- Materials Science
- Nanotechnology
- Optoelectronics
Background:
- Conventional organic light-emitting diodes (OLEDs) often require specialized emitters for near-infrared (NIR) light.
- Achieving color-tunable emission, especially in the NIR spectrum, remains a challenge in OLED technology.
Purpose of the Study:
- To develop a color-tuning strategy for high-performance, optically impaired OLEDs by extending red-emitting materials into the NIR region.
- To investigate the use of localized surface plasmon resonance (LSPR) via modified nanoparticle-based anodes to achieve tunable NIR emission.
- To eliminate the need for dedicated NIR emitters in OLEDs by leveraging existing red-emitting materials.
Main Methods:
- Utilized silver (Ag) and gold (Au) nanoparticle-based anodes coated with titanium dioxide (TiO2).
- Applied various rapid thermal annealing (RTA) treatments (200 °C, 400 °C, 600 °C) to modify nanoparticle morphology.
- Compared three TiO2 coating techniques: overcoating, stacking, and sandwiching, analyzing their effect on LSPR and electroluminescence (EL) spectra using UV-vis spectroscopy and scanning electron microscopy.
Main Results:
- Ag nanoparticles demonstrated stronger LSPR responses and greater color-tunability compared to Au nanoparticles.
- RTA promoted desirable island-like nanoparticle growth and minimized agglomeration, while TiO2 coatings enhanced island formation and peak definition.
- The overcoating technique red-shifted emission from 663 nm to 723 nm, achieving 12.91% external quantum efficiency and a 2.41 V turn-on voltage.
- The TiO2 stacking configuration produced a broad EL spectrum (199 nm FWHM) from 643 nm to 842 nm.
Conclusions:
- Ag nanoparticle-based anodes are highly promising for creating color-tunable NIR OLEDs.
- The developed TiO2 stacking coating technique offers potential for broad-wavelength emission applications in OLEDs.
- This LSPR-based strategy provides an effective method for extending the emission range of conventional red emitters into the NIR spectrum.
