1
|
Chen L, Li D, Wang A, Guo W, Su X, Shang J, Du W, Liu S, Ma Z. Negative corona discharge strategy for efficient quantum dot light-emitting diodes. OPTICS LETTERS 2024; 49:3392-3395. [PMID: 38875628 DOI: 10.1364/ol.515282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 05/24/2024] [Indexed: 06/16/2024]
Abstract
In colloid quantum dot light-emitting diodes (QLEDs), the control of interface states between ZnO and quantum dots (QDs) plays a vital role. We present a straightforward and efficient method using a negative corona discharge to modify the QD film, creating a dipole moment at the interface of QDs and magnesium-doped ZnO (ZnMgO) for balanced charge carrier distribution within the QDs. This process boosts external quantum efficiencies in red, green, and blue QLEDs to 17.71%, 14.53%, and 9.04% respectively. Notably, optimized devices exhibit significant enhancements, especially at lower brightness levels (1000 to 10,000 cd·m-2), vital for applications in mobile displays, TV screens, and indoor lighting.
Collapse
|
2
|
Ma S, Cao F, Jia G, Wu Q, Wang S, Yang X. Blue ZnSeTe quantum dot light-emitting diodes with low efficiency roll-off enabled by an in situ hybridization of ZnMgO nanoparticles and amino alcohol molecules. NANOSCALE 2024; 16:10441-10447. [PMID: 38742531 DOI: 10.1039/d4nr01515k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
ZnSeTe quantum dots (QDs) have been employed as promising emitters for blue QD-based light-emitting diodes (QLEDs) due to their unique optoelectronic properties and environmental friendliness. However, such QLEDs usually suffer from serious efficiency roll-off primarily stemming from exciton loss at the interface of the QD layer and the ZnMgO (ZMO) electron transport layer (ETL), which remarkably hinders their application in flat-panel displays. Herein, we propose an in situ hybridization strategy that involves the pre-introduction of amino alcohols into the reaction solution. This strategy effectively suppresses the nucleophilic condensation process by facilitating the coordination of ammonium and hydroxyl groups with metal cations (M2+, i.e. Zn2+ and Mg2+). It slows down the growth rate of ZMO nanoparticles (NPs) while simultaneously facilitating M-O coordination, resulting in the synthesis of small-sized and low-defect ZMO NPs. Notably, this in situ hybridization approach not only alleviates emission quenching at the QDs/ETL interface but also elevates the energy level of the ETL for enhancing carrier injection. We further investigated the impact of amino alcohols with varying carbon-chain lengths on the performance of ZMO NPs and the corresponding LED devices. The optimal blue ZnSeTe QLED demonstrates an impressive EQE of 8.6% with only an ∼11% drop when the current density is increased to 200 mA cm-2, and the device operating lifetime extends to over 1300 h. Conversely, the device utilizing traditionally post-treated ZMO NPs as the ETL exhibits 45% efficiency roll-off and device lifetime of merely 190 h.
Collapse
Affiliation(s)
- Shaolin Ma
- Shanghai University Microelectronic R&D Center, Shanghai University, Shanghai 201900, P. R. China
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, P. R. China.
| | - Fan Cao
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, P. R. China.
| | - Guohua Jia
- School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Qianqian Wu
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, P. R. China.
| | - Sheng Wang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, P. R. China.
| | - Xuyong Yang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, P. R. China.
| |
Collapse
|
3
|
Cai F, Zong H, Li M, Li C, Huang G, Pascual J, Liang C, Su Z, Li Z, Gao X, Hou B, Wang S, Zhou G, Du Z. Charge Carrier Regulation for Efficient Blue Quantum-Dot Light-Emitting Diodes Via a High-Mobility Coplanar Cyclopentane[ b]thiopyran Derivative. NANO LETTERS 2024; 24:5284-5291. [PMID: 38626333 PMCID: PMC11066960 DOI: 10.1021/acs.nanolett.4c00883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/18/2024]
Abstract
The performance of blue quantum dot light-emitting diodes (QLEDs) is limited by unbalanced charge injection, resulting from insufficient holes caused by low mobility or significant energy barriers. Here, we introduce an angular-shaped heteroarene based on cyclopentane[b]thiopyran (C8-SS) to modify the hole transport layer poly-N-vinylcarbazole (PVK), in blue QLEDs. C8-SS exhibits high hole mobility and conductivity due to the π···π and S···π interactions. Introducing C8-SS to PVK significantly enhanced hole mobility, increasing it by 2 orders of magnitude from 2.44 × 10-6 to 1.73 × 10-4 cm2 V-1 s-1. Benefiting from high mobility and conductivity, PVK:C8-SS-based QLEDs exhibit a low turn-on voltage (Von) of 3.2 V. More importantly, the optimized QLEDs achieve a high peak power efficiency (PE) of 7.13 lm/W, which is 2.65 times that of the control QLEDs. The as-proposed interface engineering provides a novel and effective strategy for achieving high-performance blue QLEDs in low-energy consumption lighting applications.
Collapse
Affiliation(s)
- Fensha Cai
- Key
Lab for Special Functional Materials of Ministry of Education, National
& Local Joint Engineering Research Center for High-efficiency
Display and Lighting Technology, School of Materials Science and Engineering,
and Collaborative Innovation Center of Nano Functional Materials and
Applications, Henan University, Kaifeng 475004, P. R. China
| | - Hao Zong
- Lab
of Advanced Materials, State Key Laboratory of Molecular Engineering
of Polymers, Fudan University, Shanghai 200438, P. R. China
| | - Meng Li
- Key
Lab for Special Functional Materials of Ministry of Education, National
& Local Joint Engineering Research Center for High-efficiency
Display and Lighting Technology, School of Materials Science and Engineering,
and Collaborative Innovation Center of Nano Functional Materials and
Applications, Henan University, Kaifeng 475004, P. R. China
| | - Chenguang Li
- Key
Lab for Special Functional Materials of Ministry of Education, National
& Local Joint Engineering Research Center for High-efficiency
Display and Lighting Technology, School of Materials Science and Engineering,
and Collaborative Innovation Center of Nano Functional Materials and
Applications, Henan University, Kaifeng 475004, P. R. China
| | - Guangguang Huang
- Key
Lab for Special Functional Materials of Ministry of Education, National
& Local Joint Engineering Research Center for High-efficiency
Display and Lighting Technology, School of Materials Science and Engineering,
and Collaborative Innovation Center of Nano Functional Materials and
Applications, Henan University, Kaifeng 475004, P. R. China
| | - Jorge Pascual
- Polymat, University of the Basque Country UPV/EHU, Donostia-San Sebastian 20018, Spain
| | - Chao Liang
- MOE
Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed
Matter, School of Physics, Xi’an
Jiaotong University, Xi’an 710049, P. R.
China
| | - Zhenhuang Su
- Shanghai
Synchrotron Radiation Facility (SSRF), Shanghai
Advanced Research Institute, Chinese Academy of Sciences, 239 Zhangheng Road, Shanghai 201204, P. R. China
| | - Zhe Li
- School of
Engineering and Materials Science (SEMS), Queen Mary University of London, London E1 4NS, United Kingdom
| | - Xingyu Gao
- Shanghai
Synchrotron Radiation Facility (SSRF), Shanghai
Advanced Research Institute, Chinese Academy of Sciences, 239 Zhangheng Road, Shanghai 201204, P. R. China
| | - Bo Hou
- School
of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, Wales, United Kingdom
| | - Shujie Wang
- Key
Lab for Special Functional Materials of Ministry of Education, National
& Local Joint Engineering Research Center for High-efficiency
Display and Lighting Technology, School of Materials Science and Engineering,
and Collaborative Innovation Center of Nano Functional Materials and
Applications, Henan University, Kaifeng 475004, P. R. China
| | - Gang Zhou
- Lab
of Advanced Materials, State Key Laboratory of Molecular Engineering
of Polymers, Fudan University, Shanghai 200438, P. R. China
| | - Zuliang Du
- Key
Lab for Special Functional Materials of Ministry of Education, National
& Local Joint Engineering Research Center for High-efficiency
Display and Lighting Technology, School of Materials Science and Engineering,
and Collaborative Innovation Center of Nano Functional Materials and
Applications, Henan University, Kaifeng 475004, P. R. China
| |
Collapse
|
4
|
Cai F, Li M, Zhang H, Wang Y, Li Z, Tu Y, Aldamasy MH, Jiang X, Hou B, Wang S, Du Z. Interfacial Passivation Engineering for Highly Efficient Quantum Dot Light-Emitting Diodes via Aromatic Amine-Functionalized Dipole Molecules. NANO LETTERS 2024; 24:1594-1601. [PMID: 38134416 DOI: 10.1021/acs.nanolett.3c04229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
Blue quantum dot (QD) light-emitting diodes (QLEDs) exhibit unsatisfactory operational stability and electroluminescence (EL) properties due to severe nonradiative recombination induced by large numbers of dangling bond defects and charge imbalance in QD. Herein, dipolar aromatic amine-functionalized molecules with different molecular polarities are employed to regulate charge transport and passivate interfacial defects between QD and the electron transfer layer (ETL). The results show that the stronger the molecular polarity, especially with the -CF3 groups possessing a strong electron-withdrawing capacity, the more effective the defect passivation of S and Zn dangling bonds at the QD surface. Moreover, the dipole interlayer can effectively reduce electron injection into QD at high current density, enhancing charge balance and mitigating Joule heat. Finally, blue QLEDs exhibit a peak external quantum efficiency (EQE) of 21.02% with an operational lifetime (T50 at 100 cd m-2) exceeding 4000 h.
Collapse
Affiliation(s)
- Fensha Cai
- Key Lab for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China
| | - Meng Li
- Key Lab for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China
| | - Han Zhang
- Key Lab for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China
| | - Yunqi Wang
- Key Lab for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China
| | - Zhe Li
- School of Engineering and Materials Science (SEMS), Queen Mary University of London, London E1 4NS United Kingdom
| | - Yufei Tu
- School of Electronics Information and Intelligent Manufacturing, Sias University, Xinzheng 451150, China
| | - Mahmoud H Aldamasy
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - Xiaohong Jiang
- Key Lab for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China
| | - Bo Hou
- School of Physics and Astronomy, Cardiff University, Cardiff, Wales CF24 3AA, United Kingdom
| | - Shujie Wang
- Key Lab for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China
| | - Zuliang Du
- Key Lab for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China
| |
Collapse
|