Improved Efficiency of All-Inorganic Quantum-Dot Light-Emitting Diodes via Interface Engineering
Qiulei Xu1, Xinyu Li1, Qingli Lin1
1Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, School of Materials Science and Engineering, Henan University, Kaifeng, China.
Frontiers in Chemistry
|May 12, 2020
Summary
We enhanced all-inorganic quantum dot light-emitting diodes (QLEDs) using nickel oxide (NiOₓ) by adding aluminum oxide (Al₂O₃) and molybdenum oxide (MoOₓ) interfaces. This significantly boosted efficiency by suppressing quantum dot emission quenching.
Area of Science:
- Materials Science
- Optoelectronics
- Nanotechnology
Background:
- Metal oxides offer greater stability than organic materials for quantum dot light-emitting diode (QLED) charge transport layers.
- All-inorganic QLEDs lag behind hybrid devices due to strong interactions between metal oxides and quantum dots, causing emission quenching.
Purpose of the Study:
- To improve the efficiency of all-inorganic QLEDs by addressing the emission quenching issue at the metal oxide/quantum dot interface.
- To investigate the role of interface engineering in enhancing the performance of nickel oxide (NiOₓ)-based QLEDs.
Main Methods:
- Fabrication of all-inorganic QLEDs utilizing nickel oxide (NiOₓ) as the charge transport layer.
- Interface modification using aluminum oxide (Al₂O₃) and molybdenum oxide (MoOₓ) layers between NiOₓ and quantum dots (QDs).
- Characterization of device performance, including current efficiency and external quantum efficiency (EQE).
Main Results:
- Achieved a maximum current efficiency of 20.4 cd A⁻¹ and an external quantum efficiency (EQE) of 5.5% in NiOₓ-based all-inorganic QLEDs.
- Demonstrated over 300% performance enhancement compared to pristine NiOₓ-based QLEDs through interface engineering.
- Al₂O₃ effectively suppressed NiOₓ-induced QD emission quenching, while MoOₓ reduced leakage current and improved hole injection.
Conclusions:
- Interface decoration with Al₂O₃ and MoOₓ is crucial for enhancing the performance of NiOₓ-based all-inorganic QLEDs.
- The developed interface engineering strategy significantly overcomes the limitations of metal oxide/QD interactions, leading to highly efficient devices.
- This study provides a viable pathway for developing stable and efficient all-inorganic QLEDs.
