High-performance all-inorganic CdSe/CdS nanorod-based light emitting diodes enabled by controlled electrophoretic
Nandita Biswas1, Anthony Mullen1, Lin Lyu1
1Department of Physics and Bernal Institute, University of Limerick, Castletroy, Co. Limerick, Ireland. ning.liu@ul.ie.
Nanoscale
|August 26, 2025
Summary
Electrophoretic deposition enables large-scale nanocrystal film formation for devices. This study optimized red-emitting nanocrystal light-emitting diodes (LEDs) using passivation, achieving high efficiency and low turn-on voltage.
Area of Science:
- Materials Science
- Nanotechnology
- Optoelectronics
Background:
- Electrophoretic deposition (EPD) allows macroscopic assembly of nanocrystal films.
- Nanocrystal films offer unique properties for device applications.
- All-inorganic nanocrystal light-emitting diodes (LEDs) are promising for displays.
Purpose of the Study:
- To develop a method for estimating particle charge and film morphology during EPD.
- To fabricate high-performance all-inorganic nanocrystal light-emitting diodes (LEDs).
- To optimize LED performance through surface passivation of the hole transport layer.
Main Methods:
- Combining experimental electrophoretic deposition current traces with analytical modeling.
- Fabricating vertically aligned, void-free cadmium selenide/cadmium sulfide (CdSe/CdS) nanorod (NR) films.
- Passivating nickel oxide (NiOₓ) hole transport layer (HTL) with Pentaflurothiophenol (PF-BT) molecules.
Main Results:
- Effective single particle charge and film morphology/thickness were estimated using EPD data.
- Optimized NR-LEDs achieved a 10.8% external quantum efficiency.
- The best NR-LEDs exhibited a low turn-on voltage of 2.8 V and high luminance (1735 cd m⁻²).
Conclusions:
- EPD is an effective method for large-area, cost-effective production of nanocrystal films.
- PF-BT passivation enhances NR-LED performance by reducing injection barriers and leakage current.
- This work paves the way for next-generation nanocrystal-based LED displays.
