1
|
Lee J, Jo H, Choi M, Park S, Oh J, Lee K, Bae Y, Rhee S, Roh J. Recent Progress on Quantum Dot Patterning Technologies for Commercialization of QD-LEDs: Current Status, Future Prospects, and Exploratory Approaches. SMALL METHODS 2024; 8:e2301224. [PMID: 38193264 DOI: 10.1002/smtd.202301224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/25/2023] [Indexed: 01/10/2024]
Abstract
Colloidal quantum dots (QDs) are widely regarded as advanced emissive materials with significant potential for display applications owing to their excellent optical properties such as high color purity, near-unity photoluminescence quantum yield, and size-tunable emission color. Building upon these attractive attributes, QDs have successfully garnered attention in the display market as down-conversion luminophores and now venturing into the realm of self-emissive displays, exemplified by QD light-emitting diodes (QD-LEDs). However, despite these advancements, there remains a relatively limited body of research on QD patterning technologies, which are crucial prerequisites for the successful commercialization of QD-LEDs. Thus, in this review, an overview of the current status and prospects of QD patterning technologies to accelerate the commercialization of QD-LEDs is provided. Within this review, a comprehensive investigation of three prevailing patterning methods: optical lithography, transfer printing, and inkjet printing are conducted. Furthermore, several exploratory QD patterning techniques that offer distinct advantages are introduced. This study not only paves the way for successful commercialization but also extends the potential application of QD-LEDs into uncharted frontiers.
Collapse
Affiliation(s)
- Jaeyeop Lee
- Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Hyeona Jo
- Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Minseok Choi
- Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Sangwook Park
- Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Jiyoon Oh
- Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Kyoungeun Lee
- Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Yeyun Bae
- Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Seunghyun Rhee
- Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Republic of Korea
| | - Jeongkyun Roh
- Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| |
Collapse
|
2
|
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
|
3
|
Zhang T, Wang L, Jiang R, Wu Z, Han Y, Xu B, Jin X, Li Q, Bai J. Well-type thick-shell quantum dots combined with double hole transport layers device structure assisted realization of high-performance quantum dot light-emitting diodes. OPTICS EXPRESS 2024; 32:20618-20628. [PMID: 38859439 DOI: 10.1364/oe.523932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 05/12/2024] [Indexed: 06/12/2024]
Abstract
Quantum dot (QD) light-emitting diodes (QLEDs) are promising for next-generation lighting and displays. Considering the optimization design of both the QD and device structure is expected to improve the QLED's performance significantly but has rarely been reported. Here, we use the thick-shell QDs combined with a dual-hole transport layer device structure to construct a high-efficiency QLED. The optimized thick-shell QDs with CdS/CdSe/CdS/ZnS seed/spherical quantum well/shell/shell geometry exhibit a high photoluminescence quantum yield of 96% at a shell thickness of 5.9 nm. The intermediate emissive CdSe layer with coherent strain ensures defect-free growth of the thick CdS and ZnS outer shells. Based on the orthogonal solvents assisted Poly-TPD&PVK dual-hole transport layer device architecture, the champion QLED achieved a maximum external quantum efficiency of 22.5% and a maximum luminance of 259955 cd m-2, which are 1.6 and 3.7 times that of thin-shell QDs based devices with single hole transport layer, respectively. Our study provides a feasible idea for further improving the performance of QLED devices.
Collapse
|
4
|
Zhang W, Li B, Chang C, Chen F, Zhang Q, Lin Q, Wang L, Yan J, Wang F, Chong Y, Du Z, Fan F, Shen H. Stable and efficient pure blue quantum-dot LEDs enabled by inserting an anti-oxidation layer. Nat Commun 2024; 15:783. [PMID: 38278797 PMCID: PMC10817946 DOI: 10.1038/s41467-024-44894-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 01/09/2024] [Indexed: 01/28/2024] Open
Abstract
The efficiency and stability of red and green quantum-dot light-emitting diodes have already met the requirements for commercialization in displays. However, the poor stability of the blue ones, particularly pure blue color, is hindering the commercialization of full-color quantum-dot light-emitting diode technology. Severe hole accumulation at the blue quantum-dot/hole-transport layer interface makes the hole-transport layer prone to oxidation, limiting the device operational lifetime. Here, we propose inserting an anti-oxidation layer (poly(p-phenylene benzobisoxazole)) between this interface to take in some holes from the hole-transport layer, which mitigates the oxidation-induced device degradation, enabling a T50 (time for the luminance decreasing by 50%) of more than 41,000 h with an initial brightness of 100 cd m-2 in pure blue devices. Meanwhile, the inserted transition layer facilitates hole injection and helps reduce electron leakage, leading to a peak external quantum efficiency of 23%.
Collapse
Affiliation(s)
- Wenjing Zhang
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China
| | - Bo Li
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, CAS Key Laboratory of Microscale Magnetic Resonance, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China
| | - Chun Chang
- Key Laboratory of Nondestructive Testing Ministry of Education, Nanchang Hangkong University, 330063, Nanchang, China
| | - Fei Chen
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China.
| | - Qin Zhang
- Key Laboratory of Nondestructive Testing Ministry of Education, Nanchang Hangkong University, 330063, Nanchang, China
| | - Qingli Lin
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China
| | - Lei Wang
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China
| | - Jinhang Yan
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China
| | - Fangfang Wang
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China
| | - Yihua Chong
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China
| | - Zuliang Du
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China
| | - Fengjia Fan
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, CAS Key Laboratory of Microscale Magnetic Resonance, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China.
| | - Huaibin Shen
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, Henan University, 475004, Kaifeng, China.
| |
Collapse
|
5
|
Liu Y, Yan M, Shu J, He H, Wang Z, Qin Z, Wang Y, Zhang Y. Enhanced Performance and High Resistance to Efficiency Degradation of Blue Quantum-Dot Light-Emitting Diodes Using the Lewis Base Blended Hole-Transporting Layers. ACS APPLIED MATERIALS & INTERFACES 2024; 16:1251-1258. [PMID: 38129975 DOI: 10.1021/acsami.3c17141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
The distinctive characteristics of blue quantum dots (QDs) such as their deep valence band and large bandgap give rise to an elevated hole injection barrier between the hole transport layers (HTLs) and the QD active layer. This results in an imbalance of carrier transport and injection across the device, leading to a degrading performance in QD light-emitting diodes (QLEDs). In this paper, high-efficiency and low-efficiency degradation blue CdSe/CdS/ZnS QLEDs were fabricated by using the Lewis base, 1,2-bis(diphenylphosphino)ethane (DPPE), blended with poly(9-vinylcarbazole) (PVK) (DPPE:PVK) as HTLs. The device performance of blue QLEDs can be finely adjusted by manipulating the blending ratio between DPPE and PVK. When 4 wt % DPPE was blended with PVK (4 wt % DPPE:PVK) as the HTL, the device achieved its optimal performance. Compared to the device with neat PVK as the HTL, the turn-on voltage of blue QLEDs with the 4 wt % DPPE:PVK HTL is reduced from 3.21 to 2.9 V. The maximum current efficiency (CE) and external quantum efficiency (EQE) of blue QLEDs increase from 2.92 cd A-1 and 5.89% in neat PVK to 5.75 cd A-1 and 11.75% for the 4 wt % DPPE:PVK HTL. Furthermore, the QLEDs incorporating DPPE:PVK HTLs exhibited exceptional resistance to efficiency degradation (EQE = 8.83%@L = 12,000 cd m-2 for 4 wt % DPPE:PVK as the HTL and EQE = 2.80%@L = 12,000 cd m-2 for neat PVK as the HTL). A more in-depth analysis reveals that enhanced device performance results from the chelating and bridging effect of the bidentate ligand Lewis base DPPE. These effects strengthen the binding of free metal ions in the blue QDs, reduce the charge barriers, enhance the contact between the HTLs and the QD active layer, and ultimately improve hole injection.
Collapse
Affiliation(s)
- Yuyu Liu
- School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, P. R. China
| | - Minming Yan
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, P. R. China
| | - Jia Shu
- School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, P. R. China
| | - Hongwei He
- School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, P. R. China
| | - Zi Wang
- School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, P. R. China
| | - Ziyu Qin
- School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, P. R. China
| | - Yunwei Wang
- School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, P. R. China
| | - Yong Zhang
- School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, P. R. China
- Guangdong Engineering Technology Research Center of Low Carbon and Advanced Energy Materials, Guangzhou 510631, P. R. China
| |
Collapse
|
6
|
Li L, Luo Y, Wu Q, Wang L, Jia G, Chen T, Zhang C, Yang X. Efficient and bright green InP quantum dot light-emitting diodes enabled by a self-assembled dipole interface monolayer. NANOSCALE 2023; 15:2837-2842. [PMID: 36688415 DOI: 10.1039/d2nr06618a] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The interfacial state between the hole transport layer (HTL) and quantum dots (QDs) plays a crucial role in the optoelectronic performance of light-emitting diodes. Herein, we reported an efficient and bright green indium phosphide (InP) QD-based light-emitting diode (LED) by introducing a self-assembled monolayer of 4-bromo-2-fluorothiophenol (SAM-BFTP) molecule to improve interfacial charge transport in LED devices. The molecular dipole layer at the interface of the QD layer and HTL not only reduces the energy barrier of holes injected into QDs through vacuum energy level shift but also inhibits the fluorescence quenching of QDs caused by the HTL. Moreover, copper ions doped into phosphomolybdic acid (Cu:PMA) is selected as the hole injection layer (HIL) into the device system based on the SAM-BFTP molecule, and as a result, a green InP QD LED (QLED) with a maximum external quantum efficiency (EQE) of 8.46% and a luminance of 18 356 cd m-2 was realized. This work can inform and underpin the future development of InP-based QLEDs with concurrent high efficiency and brightness.
Collapse
Affiliation(s)
- Lufa Li
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
| | - Yaning Luo
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
| | - Qianqian Wu
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
| | - Lin Wang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
| | - Guohua Jia
- School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia
| | - Tao Chen
- Office of Admissions and Career Services, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Chengxi Zhang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
| | - Xuyong Yang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China.
| |
Collapse
|
7
|
Zhu Z, Li Y, Guan Z, Wu Y, Zeng Z, Tsang SW, Liu S, Huang X, Lee CS. Spatial Control of the Hole Accumulation Zone for Hole-Dominated Perovskite Light-Emitting Diodes by Inserting a CsAc Layer. ACS APPLIED MATERIALS & INTERFACES 2023; 15:7044-7052. [PMID: 36705641 DOI: 10.1021/acsami.2c19230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Perovskites show efficient electroluminescence and are expected to have wide applications in light-emitting diodes (LEDs). However, owing to the unbalanced electron-hole transport properties of some highly luminescent perovskites, a fundamental challenge is that the exciton recombination zone of perovskite LEDs (PeLEDs) typically overlaps with an accumulation of the major carrier. It is known to reduce the performances of PeLEDs, leading to a reduction of efficiency and operation stability due to Auger recombination. To address this issue in a hole-dominated blue PeLED, we propose to insert a cesium acetate (CsAc) layer between the hole transport layer (HTL) and the hole-dominant perovskite layer. Electronic properties indicate that the hole accumulation zone of the device with the CsAc layer shifts away from the perovskite/ETL interface, i.e., the recombination zone, to the HTL/CsAc interface. Separation of the hole accumulation region and the exciton recombination zones substantially suppresses exciton quenching. Moreover, the CsAc layer can also improve the photophysical properties of the perovskite film by providing an extra Cs source to interact with the defect site of unreacted PbBr2 in the perovskite film and enhance the crystallinity of the perovskite with an enlarged crystal grain size. As a result, the external quantum efficiency (EQE) of the sky-blue PeLEDs shows considerable improvement from 5.3 to 9.2% upon inserting the CsAc layer.
Collapse
Affiliation(s)
- Zhaohua Zhu
- Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China
- Department of Chemistry, City University of Hong Kong, Kowloon 000000, Hong Kong SAR, P. R. China
| | - Yang Li
- Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China
- Department of Chemistry, City University of Hong Kong, Kowloon 000000, Hong Kong SAR, P. R. China
| | - Zhiqiang Guan
- Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China
- Department of Chemistry, City University of Hong Kong, Kowloon 000000, Hong Kong SAR, P. R. China
| | - Yan Wu
- Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China
- Department of Chemistry, City University of Hong Kong, Kowloon 000000, Hong Kong SAR, P. R. China
| | - Zixin Zeng
- Department of Material Science and Engineering, City University of Hong Kong, Kowloon 000000, Hong Kong SAR, P. R. China
| | - Sai-Wing Tsang
- Department of Material Science and Engineering, City University of Hong Kong, Kowloon 000000, Hong Kong SAR, P. R. China
| | - Shihao Liu
- Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China
- Department of Chemistry, City University of Hong Kong, Kowloon 000000, Hong Kong SAR, P. R. China
| | - Xiao Huang
- Institute of Advanced Materials (IAM), Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Chun-Sing Lee
- Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong SAR 000000, P. R. China
- Department of Chemistry, City University of Hong Kong, Kowloon 000000, Hong Kong SAR, P. R. China
| |
Collapse
|
8
|
Jeong JH, Kim MG, Ma JH, Park MH, Ha HJ, Kang SJ, Maeng MJ, Kim YD, Park Y, Kang SJ. Improving the Performance of Solution-Processed Quantum Dot Light-Emitting Diodes via a HfO x Interfacial Layer. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8977. [PMID: 36556781 PMCID: PMC9781304 DOI: 10.3390/ma15248977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/11/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
One of the major obstacles in the way of high-performance quantum dot light-emitting diodes (QLEDs) is the charge imbalance arising from more efficient electron injection into the emission layer than the hole injection. In previous studies, a balanced charge injection was often achieved by lowering the electron injection efficiency; however, high performance next-generation QLEDs require the hole injection efficiency to be enhanced to the level of electron injection efficiency. Here, we introduce a solution-processed HfOx layer for the enhanced hole injection efficiency. A large amount of oxygen vacancies in the HfOx films creates gap states that lower the hole injection barrier between the anode and the emission layer, resulting in enhanced light-emitting characteristics. The insertion of the HfOx layer increased the luminance of the device to 166,600 cd/m2, and the current efficiency and external quantum efficiency to 16.6 cd/A and 3.68%, respectively, compared with the values of 63,673 cd/m2, 7.37 cd/A, and 1.64% for the device without HfOx layer. The enhanced light-emitting characteristics of the device were elucidated by X-ray photoelectron, ultra-violet photoelectron, and UV-visible spectroscopy. Our results suggest that the insertion of the HfOx layer is a useful method for improving the light-emitting properties of QLEDs.
Collapse
Affiliation(s)
- Jun Hyung Jeong
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min Gye Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Jin Hyun Ma
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min Ho Park
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Hyoun Ji Ha
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Seong Jae Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min-Jae Maeng
- Department of Physics and Research Institute of Basic Sciences, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Young Duck Kim
- Department of Physics and Research Institute of Basic Sciences, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Yongsup Park
- Department of Physics and Research Institute of Basic Sciences, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| |
Collapse
|
9
|
Hu Y, Cao S, Qiu P, Yu M, Wei H. All-Inorganic Perovskite Quantum Dot-Based Blue Light-Emitting Diodes: Recent Advances and Strategies. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:4372. [PMID: 36558224 PMCID: PMC9781770 DOI: 10.3390/nano12244372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/02/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Light-emitting diodes (LEDs) based on all-inorganic lead halide perovskite quantum dots (PQDs) have undergone rapid development especially in the past five years, and external quantum efficiencies (EQEs) of the corresponding green- and red-emitting devices have exceeded 23%. However, the blue-emitting devices are facing greater challenges than their counterparts, and their poor luminous efficiency has hindered the display application of PQD-based LEDs (PeQLEDs). This review focuses on the key challenges of blue-emitting PeQLEDs including low EQEs, short operating lifetime, and spectral instability, and discusses the essential mechanism by referring to the latest research. We then systematically summarize the development of preparation methods of blue emission PQDs, as well as the current strategies on alleviating the poor device performance involved in composition engineering, ligand engineering, surface/interface engineering, and device structural engineering. Ultimately, suggestions and outlooks are proposed around the major challenges and future research direction of blue PeQLEDs.
Collapse
Affiliation(s)
- Yuyu Hu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto–Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Shijie Cao
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto–Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Peng Qiu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto–Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Meina Yu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Huiyun Wei
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto–Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
- Engineering Research Center of Clinical Functional Materials and Diagnosis & Treatment Devices of Zhejiang Province, Wenzhou Institute, Wenzhou Institute of Biomaterials & Engineering, University of Chinese Academy of Sciences, Wenzhou 325027, China
| |
Collapse
|
10
|
Demir Gİ, Demir S, Tekin A. 2D‐FFCASP—A New Approach for 2D Structure Prediction Applied to Self‐Assemblies of DNA Bases. ADVANCED THEORY AND SIMULATIONS 2022. [DOI: 10.1002/adts.202200308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Gözde İniş Demir
- Informatics Institute Istanbul Technical University Maslak Istanbul 34469 Turkey
| | - Samet Demir
- Informatics Institute Istanbul Technical University Maslak Istanbul 34469 Turkey
- TÜBİTAK Research Institute for Fundamental Sciences Gebze Kocaeli 41470 Turkey
| | - Adem Tekin
- Informatics Institute Istanbul Technical University Maslak Istanbul 34469 Turkey
- TÜBİTAK Research Institute for Fundamental Sciences Gebze Kocaeli 41470 Turkey
| |
Collapse
|
11
|
Lv P, Wang L, Li X, Yang C, Yin Z, Tang A. Electroluminescent white light-emitting diodes with cadimum-free Cu-In-Zn-S nanocrystals sandwiched between two TFB layers. OPTICS LETTERS 2022; 47:2722-2725. [PMID: 35648914 DOI: 10.1364/ol.458397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
A high color rendering index (CRI) and stable spectra under different voltages are important parameters for large-area planar light sources. However, the spectrum of most electroluminescent white light-emitting diodes (el-WLEDs) with a single emissive layer (EML) varies with a changing voltage. Herein, an el-WLED is fabricated based on Cd-free Cu-In-Zn-S (CIZS)/ZnS nanocrystals (NCs) and poly [(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)] (TFB) as double EMLs, which exhibit white-light emission with a high CRI value of 91 and commission internationale de l'éclairage (CIE) color coordinates of (0.33, 0.33). Meanwhile, it has a stable spectrum under voltage up to 7 V and a maximum luminance up to 679 cd/m2 with a low turn-on voltage of 2.2 V. This work provides a foundation for Cd-free el-WLEDs with high CRI and stable spectra.
Collapse
|
12
|
Zvaigzne M, Alexandrov A, Tkach A, Lypenko D, Nabiev I, Samokhvalov P. Optimizing the PMMA Electron-Blocking Layer of Quantum Dot Light-Emitting Diodes. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2014. [PMID: 34443846 PMCID: PMC8401809 DOI: 10.3390/nano11082014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 02/04/2023]
Abstract
Quantum dots (QDs) are promising candidates for producing bright, color-pure, cost-efficient, and long-lasting QD-based light-emitting diodes (QDLEDs). However, one of the significant problems in achieving high efficiency of QDLEDs is the imbalance between the rates of charge-carrier injection into the emissive QD layer and their transport through the device components. Here we investigated the effect of the parameters of the deposition of a poly (methyl methacrylate) (PMMA) electron-blocking layer (EBL), such as PMMA solution concentration, on the characteristics of EBL-enhanced QDLEDs. A series of devices was fabricated with the PMMA layer formed from acetone solutions with concentrations ranging from 0.05 to 1.2 mg/mL. The addition of the PMMA layer allowed for an increase of the maximum luminance of QDLED by a factor of four compared to the control device without EBL, that is, to 18,671 cd/m2, with the current efficiency increased by an order of magnitude and the turn-on voltage decreased by ~1 V. At the same time, we have demonstrated that each particular QDLED characteristic has a maximum at a specific PMMA layer thickness; therefore, variation of the EBL deposition conditions could serve as an additional parameter space when other QDLED optimization approaches are being developed or implied in future solid-state lighting and display devices.
Collapse
Affiliation(s)
- Mariya Zvaigzne
- Laboratory of Nano-Bioengineering, Institute of Engineering Physics for Biomedicine, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 31 Kashirskoe Highway, 115409 Moscow, Russia; (A.T.); (I.N.)
| | - Alexei Alexandrov
- Laboratory of Electronic and Photonic Processes in Polymeric Nanomaterials, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, 31, bld.4, Leninsky Prospect, 119071 Moscow, Russia; (A.A.); (D.L.)
| | - Anastasia Tkach
- Laboratory of Nano-Bioengineering, Institute of Engineering Physics for Biomedicine, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 31 Kashirskoe Highway, 115409 Moscow, Russia; (A.T.); (I.N.)
| | - Dmitriy Lypenko
- Laboratory of Electronic and Photonic Processes in Polymeric Nanomaterials, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, 31, bld.4, Leninsky Prospect, 119071 Moscow, Russia; (A.A.); (D.L.)
| | - Igor Nabiev
- Laboratory of Nano-Bioengineering, Institute of Engineering Physics for Biomedicine, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 31 Kashirskoe Highway, 115409 Moscow, Russia; (A.T.); (I.N.)
- Laboratory of Immunopathology, I.M. Sechenov First Moscow State Medical University, 8-2 Trubetskaya Str., 119991 Moscow, Russia
- Laboratoire de Recherche en Nanosciences, Université de Reims Champagne-Ardenne, 51 rue Cognacq Jay, 51100 Reims, France
| | - Pavel Samokhvalov
- Laboratory of Nano-Bioengineering, Institute of Engineering Physics for Biomedicine, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 31 Kashirskoe Highway, 115409 Moscow, Russia; (A.T.); (I.N.)
| |
Collapse
|
13
|
Chen WS, Yang SH, Tseng WC, Chen WWS, Lu YC. Utilization of Nanoporous Nickel Oxide as the Hole Injection Layer for Quantum Dot Light-Emitting Diodes. ACS OMEGA 2021; 6:13447-13455. [PMID: 34056492 PMCID: PMC8158834 DOI: 10.1021/acsomega.1c01618] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 04/29/2021] [Indexed: 06/10/2023]
Abstract
Nickel oxide (NiOx) has been extensively investigated as the hole injection layer (HIL) for many optoelectronic devices because of its excellent hole mobility, high environmental stability, and low-cost fabrication. In this research, a NiOx thin film and nanoporous layers (NPLs) have been utilized as the HIL for the fabrication of quantum dot light-emitting diodes (QLEDs). The obtained NiOx NPLs have spongelike nanostructures that possess a larger surface area to enhance carrier injection and to lower the turn-on voltage as compared with the NiOx thin film. The energy levels of NiOx were slightly downshifted by incorporating the nanoporous structure. The amount of Ni2O3 species is higher than that of NiO in the NiOx NPL, confirming its good hole transport ability. The best QLED was achieved with a 30 nm thick NiOx NPL, exhibiting a maximum brightness of 68 646 cd m-2, a current efficiency of 7.60 cd A-1, and a low turn-on voltage of 3.4 V. More balanced carrier transport from the NiOx NPL and ZnO NPs/polyethylenimine ethoxylated (PEIE) is responsible for the improved device performance.
Collapse
Affiliation(s)
- Wei-Sheng Chen
- Institute
of Lighting and Energy Photonics, College of Photonics, National Chiao Tung University, No. 301, Gaofa 3rd Road, Guiren District, Tainan 71150, Taiwan, ROC
| | - Sheng-Hsiung Yang
- Institute
of Lighting and Energy Photonics, College of Photonics, National Chiao Tung University, No. 301, Gaofa 3rd Road, Guiren District, Tainan 71150, Taiwan, ROC
| | - Wei-Cheng Tseng
- Opulence
Optronics Co., Ltd., 3F, No. 1, Zhanye 1st Road, East District, Hsinchu 30091, Taiwan, ROC
| | - Wilson Wei-Sheng Chen
- Opulence
Optronics Co., Ltd., 3F, No. 1, Zhanye 1st Road, East District, Hsinchu 30091, Taiwan, ROC
| | - Yuan-Chang Lu
- Opulence
Optronics Co., Ltd., 3F, No. 1, Zhanye 1st Road, East District, Hsinchu 30091, Taiwan, ROC
| |
Collapse
|
14
|
Lee W, Lee C, Kim B, Choi Y, Chae H. Enhancing the efficiency of solution-processed inverted quantum dot light-emitting diodes via ligand modification with 6-mercaptohexanol. OPTICS LETTERS 2021; 46:1434-1437. [PMID: 33720218 DOI: 10.1364/ol.414574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
In this Letter, the surface hydrophilicity of the quantum dot (QD) emitting layer (EML) was modified via a ligand exchange to prevent QD EML damage upon hole transport layer (HTL) deposition for all-solution-processed inverted QD-light-emitting diodes (QLEDs). The conventional hydrophobic oleic acid ligand (OA-QDs) was partially replaced with a hydrophilic 6-mercaptohexanol (OH-QDs) through a one-pot ligand exchange. Owing to this replacement, the contact angle of a water droplet on the OH-QD films was reduced to 71.7° from 89.5° on the OA-QD films, indicating the conversion to hydrophilic hydroxyl ligands. The OH-QD EML maintained its integrity without any noticeable damage, even after HTL deposition, enabling all-solution processing for inverted QLEDs with well-organized multilayers. Inverted QLEDs with the OH-QD EMLs were compared with those with OA-QD EMLs; the maximum current efficiency of the device with the OH-QD EML significantly improved to 39.0 cd A-1 from 5.3 cd A-1, and the peak external quantum efficiency improved to 9.3% from 1.2%, which is a seven-fold increase over the OA-QD device. This approach is believed to be effective for forming solid QD films with resistance to chlorobenzene, a representative HTL solvent, and consequently contributes to high-efficiency all-solution-processed inverted QLEDs.
Collapse
|
15
|
Kim M, Lee N, Yang JH, Han CW, Kim HM, Han W, Park HH, Yang H, Kim J. High-efficiency quantum dot light-emitting diodes based on Li-doped TiO 2 nanoparticles as an alternative electron transport layer. NANOSCALE 2021; 13:2838-2842. [PMID: 33508043 DOI: 10.1039/d0nr05920j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report high-efficiency quantum dot light-emitting diodes (QLEDs) with Li-doped TiO2 nanoparticles (NPs) as an alternative electron transport layer (ETL). Colloidally stable TiO2 NPs are applied as ETLs of inverted structured QLEDs and the effect of the addition of lithium (Li) to TiO2 NPs on device characteristics is studied in detail. Compared to pristine TiO2 NPs, Li-doped ones are found to be beneficial for the charge balance in the emitting layer of QLEDs mainly by means of their upshifted conduction band minimum, which in turn limits electron injection. A green QLED with 5% Li-doped TiO2 NPs produces a maximum luminance of 169 790 cd m-2, an EQE of 10.27%, and a current efficiency of 40.97 cd A-1, which indicate the best device performances to date among QLEDs with non-ZnO inorganic ETLs. These results indicate that Li-doped TiO2 NPs show great promise for use as a solution-based inorganic ETL for future QLEDs.
Collapse
Affiliation(s)
- Moonbon Kim
- Department of Advanced Materials Engineering, Kyonggi University, Suwon 16227, Republic of Korea.
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Han YJ, Kang KT, Ju BK, Cho KH. Effect of Time-Dependent Characteristics of ZnO Nanoparticles Electron Transport Layer Improved by Intense-Pulsed Light Post-Treatment on Hole-Electron Injection Balance of Quantum-Dot Light-Emitting Diodes. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E5041. [PMID: 33182376 PMCID: PMC7664918 DOI: 10.3390/ma13215041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 10/28/2020] [Accepted: 11/05/2020] [Indexed: 11/17/2022]
Abstract
We investigated the effect of intense-pulsed light (IPL) post-treatment on the time-dependent characteristics of ZnO nanoparticles (NPs) used as an electron transport layer (ETL) of quantum-dot light-emitting diodes (QLEDs). The time-dependent characteristics of the charge injection balance in QLEDs was observed by fabrication and analysis of single carrier devices (SCDs), and it was confirmed that the time-dependent characteristics of the ZnO NPs affect the device characteristics of QLEDs. Stabilization of the ZnO NPs film properties for improvement of the charge injection balance in QLEDs was achieved by controlling the current density characteristics via filling of the oxygen vacancies by IPL post-treatment.
Collapse
Affiliation(s)
- Young Joon Han
- Manufacturing Process Platform Research and Development Department, Korea Institute of Industrial Technology (KITECH), 143 Hanggaul-ro, Sangnok-gu, Ansan-si 15588, Korea; (Y.J.H.); (K.-T.K.)
- Department of Electrical and Electronics Engineering, College of Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Kyung-Tae Kang
- Manufacturing Process Platform Research and Development Department, Korea Institute of Industrial Technology (KITECH), 143 Hanggaul-ro, Sangnok-gu, Ansan-si 15588, Korea; (Y.J.H.); (K.-T.K.)
| | - Byeong-Kwon Ju
- Department of Electrical and Electronics Engineering, College of Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Kwan Hyun Cho
- Manufacturing Process Platform Research and Development Department, Korea Institute of Industrial Technology (KITECH), 143 Hanggaul-ro, Sangnok-gu, Ansan-si 15588, Korea; (Y.J.H.); (K.-T.K.)
| |
Collapse
|
17
|
Lee Y, Yang I, Tan HH, Jagadish C, Karuturi SK. Monocrystalline InP Thin Films with Tunable Surface Morphology and Energy Band gap. ACS APPLIED MATERIALS & INTERFACES 2020; 12:36380-36388. [PMID: 32692158 DOI: 10.1021/acsami.0c10370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
InP is currently being used in various (opto)electronic and energy device applications. However, the high cost of InP substrates and associated epitaxial growth techniques has been huge impediments for its widespread use. Here, large-area monocrystalline InP thin films are demonstrated via a convenient cracking method, and the InP thin films show material properties identical to their bulk counterparts. Furthermore, the same substrate can be reused for the production of additional InP thin films. This cracking technique is also shown to be a versatile tool to form an ultrasmooth surface or a microscale periodic triangular grating structure on the surface, depending on the orientation of the donor substrate used. Strain-induced band gap energy shift is also observed in localized regions of the thin film with a grating structure. The simplicity of this technique, which does not require any sophisticated equipment and complex fabrication process, is promising to reduce the cost of InP thin-film devices.
Collapse
Affiliation(s)
- Yonghwan Lee
- Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Convergence Materials Research Center, Gumi Electronics and Information Technology Research Institute, Cheomdangieop 1-ro 17, Sandong-myeon, Gumi 39171, Republic of Korea
| | - Inseok Yang
- Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Advanced LED Development Group, Device Solutions, Samsung Electronics Company, Ltd., Yongin-si, Gyeonggi-do 17113, Republic of Korea
| | - Hark Hoe Tan
- Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Chennupati Jagadish
- Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Siva Krishna Karuturi
- Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Research School of Electrical, Energy, and Materials Engineering, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| |
Collapse
|
18
|
Jia H, Wang F, Tan Z. Material and device engineering for high-performance blue quantum dot light-emitting diodes. NANOSCALE 2020; 12:13186-13224. [PMID: 32614007 DOI: 10.1039/d0nr02074e] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Colloidal quantum dots (QDs) have attracted extensive attention due to their excellent optoelectronic properties, such as high quantum efficiency, narrow emission peaks, high color saturation, high stability and solution processability. Compared with the traditional display technology, QD based light-emitting diodes (QLEDs) show broad application prospects in the field of flat-panel displays and solid-state lighting. However, for full-color displays, the efficiency and lifetime of blue QLEDs are inferior to those of their green and red counterparts. Therefore, it is urgent for us to deeply understand the device physics and improve the performance of blue QLEDs through material and device engineering. An in-depth understanding of the optoelectronic properties (such as the structure of electronic states, electron-phonon interactions, Auger processes, etc.) and material engineering (such as size distribution control, composition control, and surface engineering) of blue emission QDs is greatly helpful for their applications in other fields. Herein, we review the key progress in the area of blue QLEDs, including the compositions and nanostructures of blue quantum dots, advances in the device architectures and the improvement of the device lifetime of blue QLEDs. The key factors that influence the blue device performance, including the nanostructure design and surface modification of QDs, interface engineering and architecture design of devices are discussed, aiming to propose possible solutions for these challenges, which will help to promote the commercialization process of QLEDs.
Collapse
Affiliation(s)
- Haoran Jia
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Fuzhi Wang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China
| | - Zhan'ao Tan
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
| |
Collapse
|
19
|
Alexandrov A, Zvaigzne M, Lypenko D, Nabiev I, Samokhvalov P. Al-, Ga-, Mg-, or Li-doped zinc oxide nanoparticles as electron transport layers for quantum dot light-emitting diodes. Sci Rep 2020; 10:7496. [PMID: 32366882 PMCID: PMC7198560 DOI: 10.1038/s41598-020-64263-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 04/14/2020] [Indexed: 11/09/2022] Open
Abstract
Colloidal quantum dots and other semiconductor nanocrystals are essential components of next-generation lighting and display devices. Due to their easily tunable and narrow emission band and near-unity fluorescence quantum yield, they allow cost-efficient fabrication of bright, pure-color and wide-gamut light emitting diodes (LEDs) and displays. A critical improvement in the quantum dot LED (QLED) technology was achieved when zinc oxide nanoparticles (NPs) were first introduced as an electron transport layer (ETL) material, which tremendously enhanced the device brightness and current efficiency due to the high mobility of electrons in ZnO and favorable alignment of its energy bands. During the next decade, the strategy of ZnO NP doping allowed the fabrication of QLEDs with a brightness of about 200 000 cd/m2 and current efficiency over 60 cd/A. On the other hand, the known ZnO doping approaches rely on a very fine tuning of the energy levels of the ZnO NP conduction band minimum; hence, selection of the appropriate dopant that would ensure the best device characteristics is often ambiguous. Here we address this problem via detailed comparison of QLEDs whose ETLs are formed by a set of ZnO NPs doped with Al, Ga, Mg, or Li. Although magnesium-doped ZnO NPs are the most common ETL material used in recently designed QLEDs, our experiments have shown that their aluminum-doped counterparts ensure better device performance in terms of brightness, current efficiency and turn-on voltage. These findings allow us to suggest ZnO NPs doped with Al as the best ETL material to be used in future QLEDs.
Collapse
Affiliation(s)
- Alexei Alexandrov
- Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow, Russian Federation
- Laboratory of Electronic and Photonic Processes in Polymeric Nanostructural Materials, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, 119071, Moscow, Russian Federation
| | - Mariya Zvaigzne
- Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow, Russian Federation
| | - Dmitri Lypenko
- Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow, Russian Federation
- Laboratory of Electronic and Photonic Processes in Polymeric Nanostructural Materials, A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, 119071, Moscow, Russian Federation
| | - Igor Nabiev
- Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow, Russian Federation.
- Laboratoire de Recherche en Nanosciences, LRN-EA4682, Université de Reims Champagne-Ardenne, 51100, Reims, France.
- I.M. Sechenov First Moscow State Medical University, 119991, Moscow, Russian Federation.
| | - Pavel Samokhvalov
- Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409, Moscow, Russian Federation.
| |
Collapse
|
20
|
Xiao H, Wang R, Gui H, Lv Z, Liu Z, Wang K. 4 Mb/s under a 3 m transmission distance using a quantum dot light-emitting diode and NRZ-OOK modulation. OPTICS LETTERS 2020; 45:1297-1300. [PMID: 32163949 DOI: 10.1364/ol.386175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 01/12/2020] [Indexed: 06/10/2023]
Abstract
We realize signal transmission with a miniature light source fabricated by a $4\; {\rm mm}^2 $4mm2 red-emissive CdSe/ZnS quantum-dot light-emitting diode (QLED) in visible light communication (VLC). The light emitted from the 60°-designed QLED transmits in free space with a data rate of 4 Mb/s at a 3 m transmission distance by using a simple modulation scheme of non-return-to-zero on-off keying. The maximum data rate of 2.5 Mb/s with a bit error rate below the forward-error-correction (FEC) limit is achieved with the optical angles of ${\rm \pm 20}^\circ $±20∘. The influences caused by the voltage, distance, and optical angle of emitting light are taken into consideration during communication. The performance of the QLED-based light source compares favorably with other solution-processed devices in efficiency, luminance, bandwidth, transmission speed, and distance. Additionally, to the best of our knowledge, this is the first report of an investigation on the application of QLED in VLC. Our results should be instructive for further investigation on QLED communication.
Collapse
|
21
|
Chiu PC, Yang SH. Improvement in hole transporting ability and device performance of quantum dot light emitting diodes. NANOSCALE ADVANCES 2020; 2:401-407. [PMID: 36133973 PMCID: PMC9419759 DOI: 10.1039/c9na00618d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/21/2019] [Indexed: 06/06/2023]
Abstract
In this research, we demonstrate a novel approach to improve the device performance of quantum dot light emitting diodes (QLEDs) by blending an additive BYK-P105 with poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) as the hole transport layer. In addition, for the first time, polyethylenimine ethoxylated (PEIE)-modified zinc oxide nanoparticles (ZnO NPs) as the electron transport layer were applied in regular-type QLEDs for achieving high device efficiency. A very high brightness of 139 909 cd m-2 and current efficiency of 27.2 cd A-1 were obtained for the optimized device with the configuration of ITO/PEDOT:PSS + BYK-P105/PVK/CdSe QDs/ZnO NPs/PEIE/LiF/Al that shows promising use in light-emitting applications.
Collapse
Affiliation(s)
- Pei-Chieh Chiu
- Institute of Lighting and Energy Photonics, College of Photonics, National Chiao Tung University No. 301, Gaofa 3rd Road, Guiren District Tainan City 71150 Taiwan Republic of China +886-6-3032535 +886-6-3032121 ext. 57895
| | - Sheng-Hsiung Yang
- Institute of Lighting and Energy Photonics, College of Photonics, National Chiao Tung University No. 301, Gaofa 3rd Road, Guiren District Tainan City 71150 Taiwan Republic of China +886-6-3032535 +886-6-3032121 ext. 57895
| |
Collapse
|
22
|
Moon H, Lee W, Kim J, Lee D, Cha S, Shin S, Chae H. Composition-tailored ZnMgO nanoparticles for electron transport layers of highly efficient and bright InP-based quantum dot light emitting diodes. Chem Commun (Camb) 2019; 55:13299-13302. [PMID: 31626256 DOI: 10.1039/c9cc06882a] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tailored-ZnMgO layers result in green-emitting InP based quantum dot light emitting diodes (QLEDs) with a maximum luminance of 13 900 cd m-2 and an external quantum efficiency (EQE) of 13.6%. This is the first report of green-emitting InP based QLEDs that exceed an EQE of 10% and a luminance of 13 000 cd m-2.
Collapse
Affiliation(s)
- Hyungsuk Moon
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea.
| | - Woosuk Lee
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea.
| | - Jungwoo Kim
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea.
| | - Daehee Lee
- Samsung Electronics, Suwon 16677, Republic of Korea
| | - Soonmin Cha
- Samsung Electronics, Suwon 16677, Republic of Korea
| | | | - Heeyeop Chae
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea. and Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| |
Collapse
|
23
|
Rhee S, Chang JH, Hahm D, Kim K, Jeong BG, Lee HJ, Lim J, Char K, Lee C, Bae WK. "Positive Incentive" Approach To Enhance the Operational Stability of Quantum Dot-Based Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2019; 11:40252-40259. [PMID: 31590488 DOI: 10.1021/acsami.9b13217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Balanced charge injection promises high efficiency of quantum dot-based light-emitting diodes (QD-LEDs). The most widely used approach to realize charge injection balance impedes the injection rate of the dominant charge carrier with energetic barriers. However, these approaches often accompany unwanted outcomes (e.g., the increase in operation voltage) that sacrifice the operational stability of devices. Herein, a "positive incentive" approach is proposed to enhance the efficiency and the operational stability of QD-LEDs. Specifically, the supply of hole, an inferior carrier than its counterpart, is facilitated by adopting a thin fullerene (C60) interlayer at the interface between the hole injection layer (MoOX) and hole transport layer (4,4'-bis(9-carbazolyl)-1,1'-biphenyl). The C60 interlayer boosts the hole current by eliminating the universal energy barrier, lowers the operation voltage of QD-LEDs, and enhances the charge balance in the QD emissive layer within the working device. Consequently, QD-LEDs benefitting from the adoption of the C60 interlayer exhibit significantly enhanced device efficiency and operation stability. Grounded on the quantitative assessment of the charge injection imbalance within the QD emissive layer, the impact of electrical parameters of QD-LEDs on their optoelectronic performance and operational stability is also discussed.
Collapse
Affiliation(s)
| | | | | | | | - Byeong Guk Jeong
- SKKU Advanced Institute of Nanotechnology , Sungkyunkwan University , Suwon 16419 , Korea
| | | | - Jaehoon Lim
- Department of Chemical Engineering , Ajou University , Suwon 16499 , Korea
| | | | | | - Wan Ki Bae
- SKKU Advanced Institute of Nanotechnology , Sungkyunkwan University , Suwon 16419 , Korea
| |
Collapse
|
24
|
Wang T, Guan X, Zhang H, Ji W. Exploring Electronic and Excitonic Processes toward Efficient Deep-Red CuInS 2/ZnS Quantum-Dot Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2019; 11:36925-36930. [PMID: 31524372 DOI: 10.1021/acsami.9b13108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The electroluminescence mechanisms in the Cd-free CuInS2/ZnS quantum dot-based light-emitting diodes (QLEDs) are systematically investigated through transient electroluminescence measurements. The results demonstrate that the characteristics of hole transporting layers (HTLs) determine the QLEDs to be activated by the direct charge injection or the energy transfer. Moreover, both the energy level alignment between the HTL and quantum dot and the carrier mobility properties of the HTLs are critical factors to affect the device performance. By choosing the suitable HTL, such as 4,4'-bis(9-carbazolyl)-2,2'-biphenyl, highly efficient deep-red (emission peak at ∼650 nm) CuInS2/ZnS QLEDs based on the single HTL can be obtained with a peak current efficiency and luminance of ∼2.0 cd/A and nearby 3000 cd/m2, respectively.
Collapse
Affiliation(s)
- Ting Wang
- Key Lab of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics , Jilin University , Changchun 130012 , China
| | - Xin Guan
- Key Lab of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics , Jilin University , Changchun 130012 , China
| | - Hanzhuang Zhang
- Key Lab of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics , Jilin University , Changchun 130012 , China
| | - Wenyu Ji
- Key Lab of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics , Jilin University , Changchun 130012 , China
| |
Collapse
|
25
|
Chen Q, Yan Y, Wu X, Lan S, Hu D, Fang Y, Lv D, Zhong J, Chen H, Guo T. High-Performance Quantum-Dot Light-Emitting Transistors Based on Vertical Organic Thin-Film Transistors. ACS APPLIED MATERIALS & INTERFACES 2019; 11:35888-35895. [PMID: 31544456 DOI: 10.1021/acsami.9b11198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this work, a novel vertical quantum-dot light-emitting transistor (VQLET) based on a vertical organic thin-film transistor is successfully fabricated. Benefiting from the new vertical architecture, the VQLET is able to afford an extremely high current density, which allows most of the organic thin film transistors (OTFT) even with low mobility (for instance, poly(3-hexylthiophene)) to drive a quantum-dot light-emitting diode (QLED), which was previously unavailable. Moreover, the hole injection barrier could be modulated by the additional gate electrode, which precisely optimizes the charge balance in the device, a critical issue in QLED, resulting in the precise control of current density and brightness of the VQLET. The VQLET shows a high performance with a maximum current efficiency of 37 cd/A. Furthermore, integrating OTFT and QLED into a single device, the VQLET features drastic advantages by realizing active matrix quantum-dot light-emitting diodes (AMQLEDs), which significantly reduces the number of transistors and frees the large area fraction occupied by transistors. Hence, these results indicate that the VQLET provides a new strategy for realizing a low-cost, solution-processed, high-performance OTFT-AMQLED for the flat panel display technology. Moreover, the novel design offers a unique method to exquisitely control the charge balance and maximize the efficiency the QLED.
Collapse
Affiliation(s)
- Qizhen Chen
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Yujie Yan
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Xiaomin Wu
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Shuqiong Lan
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Daobing Hu
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Yuan Fang
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Dongxu Lv
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Jianfeng Zhong
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Huipeng Chen
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| | - Tailiang Guo
- Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology , Fuzhou University , Fuzhou 350002 , China
| |
Collapse
|
26
|
Moon H, Lee C, Lee W, Kim J, Chae H. Stability of Quantum Dots, Quantum Dot Films, and Quantum Dot Light-Emitting Diodes for Display Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1804294. [PMID: 30650209 DOI: 10.1002/adma.201804294] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/10/2018] [Indexed: 05/06/2023]
Abstract
Quantum dots (QDs) are being highlighted in display applications for their excellent optical properties, including tunable bandgaps, narrow emission bandwidth, and high efficiency. However, issues with their stability must be overcome to achieve the next level of development. QDs are utilized in display applications for their photoluminescence (PL) and electroluminescence. The PL characteristics of QDs are applied to display or lighting applications in the form of color-conversion QD films, and the electroluminescence of QDs is utilized in quantum dot light-emitting diodes (QLEDs). Studies on the stability of QDs and QD devices in display applications are reviewed herein. QDs can be degraded by oxygen, water, thermal heating, and UV exposure. Various approaches have been developed to protect QDs from degradation by controlling the composition of their shells and ligands. Phosphorescent QDs have been protected by bulky ligands, physical incorporation in polymer matrices, and covalent bonding with polymer matrices. The stability of electroluminescent QLEDs can be enhanced by using inorganic charge transport layers and by improving charge balance. As understanding of the degradation mechanisms of QDs increases and more stable QDs and display devices are developed, QDs are expected to play critical roles in advanced display applications.
Collapse
Affiliation(s)
- Hyungsuk Moon
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Seoburo 2066, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Changmin Lee
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Seoburo 2066, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Woosuk Lee
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Seoburo 2066, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Jungwoo Kim
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Seoburo 2066, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Heeyeop Chae
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Seoburo 2066, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Seoburo 2066, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea
| |
Collapse
|
27
|
Li D, Bai J, Zhang T, Chang C, Jin X, Huang Z, Xu B, Li Q. Blue quantum dot light-emitting diodes with high luminance by improving the charge transfer balance. Chem Commun (Camb) 2019; 55:3501-3504. [PMID: 30838368 DOI: 10.1039/c9cc00230h] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The development of blue quantum dot light-emitting diodes (QLEDs) lags far behind that of the red and green ones, which hinders the practical commercialization of QLEDs. Balancing the charge transfer still remains a challenging task, because blue QD emitters have a deeper valence band (VB) that creates a great injection barrier impeding the hole transfer. Herein, we demonstrate that the charge transfer balance can be improved by using a tert-butyldimethylsilyl chloride-modified poly(p-phenylene benzobisoxazole) (TBS-PBO) blocking layer. The TBS-PBO acts well in blocking excess electron injection and preserving the emission efficiency of the QD emitter. Compared to the insulating blocking layers, TBS-PBO has good conductivity, thus keeping the current density at a high level. Our device delivers a notable luminance of 4635 cd m-2 at an external quantum efficiency (EQE) maximum of 17.4%. To the best of our knowledge, the luminance with EQE > 17% is the highest one to be reported for blue QLEDs.
Collapse
Affiliation(s)
- Dongyu Li
- School of Physics Science and Technology, Lingnan Normal University, Zhanjiang 524048, P. R. China.
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Sun Y, Jiang Y, Sun XW, Zhang S, Chen S. Beyond OLED: Efficient Quantum Dot Light-Emitting Diodes for Display and Lighting Application. CHEM REC 2019; 19:1729-1752. [PMID: 30698895 DOI: 10.1002/tcr.201800191] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Indexed: 01/25/2023]
Abstract
The unique features of solution-processed quantum dots (QDs) including emission tunability in the visible range, high-quality saturated color and outstanding intrinsic stability in environment are highly desired in various application fields. Especially, for the preparation of wide color gamut displays, QDs with high photoluminescence quantum yield are deemed as the optimal fluorescent emitter that has been utilized in the backlight for liquid crystal display. Nevertheless, the commercialization of electrically driven self-emissive quantum dot light-emitting diode (QLED) display is the ultimate target due to its merits of high contrast, slim configuration and compatibility with flexible substrate. Through the great efforts devoted to material engineering and device configuration, astonishing progresses have been made in device performance, giving the QLED technology a great chance to compete with other counterparts for next-generation displays. In this review, we retrospect the development roadmap of QLED technology and introduce the essential principles in the QLED devices. Moreover, we discuss the key factors that affect the QLED efficiency and lifetime. Finally, the advances in device architectures and pixel patterning are also summarized.
Collapse
Affiliation(s)
- Yizhe Sun
- Institute of Microelectronics, Peking University, Beijing, P. R. China, 100871.,Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, P. R. China, 518055
| | - Yibin Jiang
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, P. R. China, 518055.,State Key Lab on Advanced Displays and Optoelectronics, The Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong
| | - Xiao Wei Sun
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, P. R. China, 518055
| | - Shengdong Zhang
- Institute of Microelectronics, Peking University, Beijing, P. R. China, 100871
| | - Shuming Chen
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, P. R. China, 518055
| |
Collapse
|