Bimetallic Nanocluster-Based Light-Emitting Diodes With High External Quantum Efficiency and Saturated Red Emission
Jose V Rival1, Savita Chand2, Arijit Jana3
1Smart Materials Lab (SML), Department of Nanoscience and Technology (DNST), University of Calicut (UoC), Thenhipalam, Kerala, 673635, India.
Advanced Materials (Deerfield Beach, Fla.)
|June 11, 2025
Summary
Atomically precise gold-copper nanoclusters (NCs) achieve high external quantum efficiency (EQE) in solution-processed, non-doped red light-emitting diodes (LEDs). This breakthrough offers significant potential for advanced electro-optical devices.
Area of Science:
- Materials Science
- Nanotechnology
- Optoelectronics
Background:
- Self-emissive atomically precise metal nanoclusters (NCs) show promise for next-generation light-emitting diodes (LEDs) due to their luminescence, stability, and low toxicity.
- Achieving high external quantum efficiency (EQE) in solid-state NCs remains a significant challenge for practical applications.
Purpose of the Study:
- To synthesize and characterize a novel bimetallic gold-copper nanocluster ([Au2Cu6(Sadm)6(DPPEO)2]) for LED applications.
- To investigate the structural properties and ligand interactions influencing the nanocluster's stability and luminescence.
- To fabricate and evaluate a solution-processed, non-doped nanocluster-based LED (NC-LED) using the synthesized material.
Main Methods:
- Synthesis of bimetallic gold-copper nanoclusters stabilized by 1-adamantanethiol (HSadm) and 1,2-bis(diphenylphosphino)ethane (DPPE).
- Structural and spectroscopic analyses including single-crystal X-ray diffraction.
- Fabrication of NC-LEDs using a solution-processed technique without host materials.
Main Results:
- A highly stable bimetallic gold-copper NC, [Au2Cu6(Sadm)6(DPPEO)2], was synthesized, featuring oxidized phosphine oxide (P═O) moieties.
- The P═O moieties facilitated ligand interactions (C─H···O, C─H···π, H···H), promoting rapid crystallization and enhancing stability.
- The fabricated NC-LED demonstrated a maximum brightness of 1246 cd m⁻², a pure red emission (≈668 nm), and a record EQE of 12.60% for solution-processed, non-doped NC-LEDs.
Conclusions:
- The synthesized bimetallic gold-copper NC exhibits exceptional photo/thermal stability and high solid-state photoluminescence quantum yield (PLQY).
- The NC-LED fabricated from these nanoclusters achieved state-of-the-art performance, highlighting their potential for electro-optical devices.
- This work establishes a new benchmark for solution-processed, non-doped NC-LEDs, paving the way for advanced lighting and display technologies.
