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Zeng Y, Ma S, Cao F, Chen W, Wang Q, Jin G, Wei J, Liu F, Manna L, Yang X, Li H. High-Efficiency and Stable Colloidal One-Dimensional Core/Shell Nanorod Light-Emitting Diodes. NANO LETTERS 2024; 24:5647-5655. [PMID: 38655813 DOI: 10.1021/acs.nanolett.4c01166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Anisotropic nanocrystals such as nanorods (NRs) display unique linearly polarized emission, which is expected to break the external quantum efficiency (EQE) limit of quantum dot-based light-emitting diodes (LEDs). However, the progress in achieving a higher EQE using NRs encounters several challenges, primarily involving a low photoluminescence quantum yield (PLQY) of NRs and imbalanced charge injection in NR-LEDs. In this work, we investigated NR-LEDs based on CdSe/CdZnS/ZnS rod-in-rod NRs with a high PLQY and higher linear polarization compared to those of dot-in-rod NRs. The balanced charge injection is achieved using ZnMgO nanoparticles as the electron transport layer and poly-TPD {poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine]} as the hole transport layer. Therefore, the NR-LEDs exhibit a maximum EQE of 21.5% and a maximum luminance of >120 000 cd/m2 owing to the high level of in-plane transitions with a dipole moment of 90%. The NR-LEDs also have greatly inhibited droop in EQE under a high current density as well as outstanding operation lifetime and cycle stability.
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Affiliation(s)
- Yicheng Zeng
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Shaolin Ma
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Fan Cao
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Weiwei Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Qingya Wang
- Advanced Research Institute of Multidisciplinary Sciences, Beijing Institute of Technology, Beijing 100081, China
| | - Geyu Jin
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Jing Wei
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Fangze Liu
- Advanced Research Institute of Multidisciplinary Sciences, Beijing Institute of Technology, Beijing 100081, China
| | - Liberato Manna
- Department of Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Xuyong Yang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Hongbo Li
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
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Zeng Y, Liu X, Liu Y, Chen W, Liu F, Li H. 22% Record Efficiency in Nanorod Light-Emitting Diodes Achieved by Gradient Shells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310705. [PMID: 38377984 DOI: 10.1002/adma.202310705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 01/08/2024] [Indexed: 02/22/2024]
Abstract
The external quantum efficiency (EQE) in light-emitting diodes (LEDs) based on isotropic quantum dots has approached the theoretical limit of close to 20%. Anisotropic nanorods can break this limit by taking advantage of their directional emission. However, the progress towards higher EQE by using CdSe/CdS nanorods (NRs) faces several challenges, primarily involving the low quantum yield and unbalanced charge injection in devices. Herein, the seeded growth method is modified and anisotropic nanorods are obtained with photoluminescence quantum yield up to 98% by coating a gradient alloyed CdZnSe shell around conventional spherical CdSe seeds. This intermediate alloyed CdZnSe shell combined with a subsequent rod-shaped CdZnS/ZnS shell can effectively suppress the electron delocalization in the typical CdSe/CdS nanorods due to their small conduction bandgap offset. Additionally, this alloyed shell can reduce the hole-injection barrier and create a larger barrier for electron injection, both effects promoting a balanced injection of electrons and holes in LEDs. Hence, LEDs are reached with high brightness (160341 cd m-2) and high efficiency (EQE = 22%, current efficiency = 23.19 cd A-1), which are the highest values to date for nanorod LEDs.
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Affiliation(s)
- Yicheng Zeng
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Xiaonan Liu
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Yuan Liu
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
| | - Weiwei Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Fangze Liu
- Advanced Research Institute of Multidisciplinary Sciences, Beijing Institute of Technology, Beijing, 100081, China
| | - Hongbo Li
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China
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3
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Drake GA, Keating LP, Huang C, Shim M. Colloidal Multi-Dot Nanorods. J Am Chem Soc 2024; 146:9074-9083. [PMID: 38517010 DOI: 10.1021/jacs.3c14115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Colloidal nanorod heterostructures consisting of multiple quantum dots within a nanorod (n-DNRs, where n is the number of quantum dots within a nanorod) are synthesized with alternating segments of CdSe "dot" and CdS "rod" via solution heteroepitaxy. The reaction temperature, time dependent ripening, and asymmetry of the wurtzite lattice and the resulting anisotropy of surface ligand steric hindrance are exploited to vary the morphology of the growing quantum dot segments. The alternating CdSe and CdS growth steps can be easily repeated to increment the dot number in unidirectional or bidirectional growth regimes. As an initial exploration of electron occupation effects on their optical properties, asymmetric 2-DNRs consisting of two dots of different lengths and diameters are synthesized and are shown to exhibit a change in color and an unusual photoluminescence quantum yield increase upon photochemical doping.
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Affiliation(s)
- Gryphon A Drake
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Logan P Keating
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Conan Huang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Moonsub Shim
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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Akbali B, Boisdon C, Smith BL, Chaisrikhwun B, Wongravee K, Vilaivan T, Lima C, Huang CH, Chen TY, Goodacre R, Maher S. Focusing ion funnel-assisted ambient electrospray enables high-density and uniform deposition of non-spherical gold nanoparticles for highly sensitive surface-enhanced Raman scattering. Analyst 2023; 148:4677-4687. [PMID: 37697928 DOI: 10.1039/d3an01021j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
Surface-enhanced Raman scattering (SERS) is a powerful technique for detecting trace amounts of analytes. However, the performance of SERS substrates depends on many variables including the enhancement factor, morphology, consistency, and interaction with target analytes. In this study, we investigated, for the first time, the use of electrospray deposition (ESD) combined with a novel ambient focusing DC ion funnel to deposit a high density of gold nanoparticles (AuNPs) to generate large-area, uniform substrates for highly sensitive SERS analysis. We found that the combination of ambient ion focusing with ESD facilitated high-density and intact deposition of non-spherical NPs. This also allowed us to take advantage of a polydisperse colloidal solution of AuNPs (consisting of nanospheres and nanorods), as confirmed by finite-difference time domain (FDTD) simulations. Our SERS substrate exhibited excellent capture capacity for model analyte molecules, namely 4-aminothiophenol (4-ATP) and Rhodamine 6G (R6G), with detection limits in the region of 10-11 M and a relative standard deviation of <6% over a large area (∼500 × 500 μm2). Additionally, we assessed the quantitative performance of our SERS substrate using the R6G probe molecule. The results demonstrated excellent linearity (R2 > 0.99) over a wide concentration range (10-4 M to 10-10 M) with a detection limit of 80 pM.
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Affiliation(s)
- Baris Akbali
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Cedric Boisdon
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
| | - Barry L Smith
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
| | - Boonphop Chaisrikhwun
- Program in Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kanet Wongravee
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tirayut Vilaivan
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Cassio Lima
- Centre for Metabolomics Research, Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB, UK
| | - Chen-Han Huang
- Department of Biomedical Engineering, National Central University, Zhongli 10608, Taiwan
| | - Tsan-Yao Chen
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Royston Goodacre
- Centre for Metabolomics Research, Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB, UK
| | - Simon Maher
- Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK.
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Dalui A, Ariga K, Acharya S. Colloidal semiconductor nanocrystals: from bottom-up nanoarchitectonics to energy harvesting applications. Chem Commun (Camb) 2023; 59:10835-10865. [PMID: 37608724 DOI: 10.1039/d3cc02605a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Colloidal semiconductor nanocrystals (NCs) have been extensively investigated owing to their unique properties induced by the quantum confinement effect. The advent of colloidal synthesis routes led to the design of stable colloidal NCs with uniform size, shape, and composition. Metal oxides, phosphides, and chalcogenides (ZnE, CdE, PbE, where E = S, Se, or Te) are few of the most important monocomponent semiconductor NCs, which show excellent optoelectronic properties. The ability to build quantum confined heterostructures comprising two or more semiconductor NCs offer greater customization and tunability of properties compared to their monocomponent counterparts. More recently, the halide perovskite NCs showed exceptional optoelectronic properties for energy generation and harvesting applications. Numerous applications including photovoltaic, photodetectors, light emitting devices, catalysis, photochemical devices, and solar driven fuel cells have demonstrated using these NCs in the recent past. Overall, semiconductor NCs prepared via the colloidal synthesis route offer immense potential to become an alternative to the presently available device applications. This feature article will explore the progress of NCs syntheses with outstanding potential to control the shape and spatial dimensionality required for photovoltaic, light emitting diode, and photocatalytic applications. We also attempt to address the challenges associated with achieving high efficiency devices with the NCs and possible solutions including interface engineering, packing control, encapsulation chemistry, and device architecture engineering.
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Affiliation(s)
- Amit Dalui
- Department of Chemistry, Jogamaya Devi College, Kolkata-700026, India
| | - Katsuhiko Ariga
- Graduate School of Frontier Sciences, The University of Tokyo Kashiwa, Chiba 277-8561, Japan
- International Research Center for Materials Nanoarchitectonics (MANA) National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
| | - Somobrata Acharya
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Kolkata-700032, India.
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Chen C, Luo X, Kaplan AE, Bawendi MG, Macfarlane RJ, Bathe M. Ultrafast dense DNA functionalization of quantum dots and rods for scalable 2D array fabrication with nanoscale precision. SCIENCE ADVANCES 2023; 9:eadh8508. [PMID: 37566651 PMCID: PMC10421044 DOI: 10.1126/sciadv.adh8508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 07/14/2023] [Indexed: 08/13/2023]
Abstract
Scalable fabrication of two-dimensional (2D) arrays of quantum dots (QDs) and quantum rods (QRs) with nanoscale precision is required for numerous device applications. However, self-assembly-based fabrication of such arrays using DNA origami typically suffers from low yield due to inefficient QD and QR DNA functionalization. In addition, it is challenging to organize solution-assembled DNA origami arrays on 2D device substrates while maintaining their structural fidelity. Here, we reduced manufacturing time from a few days to a few minutes by preparing high-density DNA-conjugated QDs/QRs from organic solution using a dehydration and rehydration process. We used a surface-assisted large-scale assembly (SALSA) method to construct 2D origami lattices directly on solid substrates to template QD and QR 2D arrays with orientational control, with overall loading yields exceeding 90%. Our fabrication approach enables the scalable, high fidelity manufacturing of 2D addressable QDs and QRs with nanoscale orientational and spacing control for functional 2D photonic devices.
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Affiliation(s)
- Chi Chen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xin Luo
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexander E. K. Kaplan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Moungi G. Bawendi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Robert J. Macfarlane
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Mark Bathe
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Giri A, Park G, Jeong U. Layer-Structured Anisotropic Metal Chalcogenides: Recent Advances in Synthesis, Modulation, and Applications. Chem Rev 2023; 123:3329-3442. [PMID: 36719999 PMCID: PMC10103142 DOI: 10.1021/acs.chemrev.2c00455] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The unique electronic and catalytic properties emerging from low symmetry anisotropic (1D and 2D) metal chalcogenides (MCs) have generated tremendous interest for use in next generation electronics, optoelectronics, electrochemical energy storage devices, and chemical sensing devices. Despite many proof-of-concept demonstrations so far, the full potential of anisotropic chalcogenides has yet to be investigated. This article provides a comprehensive overview of the recent progress made in the synthesis, mechanistic understanding, property modulation strategies, and applications of the anisotropic chalcogenides. It begins with an introduction to the basic crystal structures, and then the unique physical and chemical properties of 1D and 2D MCs. Controlled synthetic routes for anisotropic MC crystals are summarized with example advances in the solution-phase synthesis, vapor-phase synthesis, and exfoliation. Several important approaches to modulate dimensions, phases, compositions, defects, and heterostructures of anisotropic MCs are discussed. Recent significant advances in applications are highlighted for electronics, optoelectronic devices, catalysts, batteries, supercapacitors, sensing platforms, and thermoelectric devices. The article ends with prospects for future opportunities and challenges to be addressed in the academic research and practical engineering of anisotropic MCs.
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Affiliation(s)
- Anupam Giri
- Department of Chemistry, Faculty of Science, University of Allahabad, Prayagraj, UP-211002, India
| | - Gyeongbae Park
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Cheongam-Ro 77, Nam-Gu, Pohang, Gyeongbuk790-784, Korea.,Functional Materials and Components R&D Group, Korea Institute of Industrial Technology, Gwahakdanji-ro 137-41, Sacheon-myeon, Gangneung, Gangwon-do25440, Republic of Korea
| | - Unyong Jeong
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Cheongam-Ro 77, Nam-Gu, Pohang, Gyeongbuk790-784, Korea
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Keating LP, Lee H, Rogers SP, Huang C, Shim M. Charging and Charged Species in Quantum Dot Light-Emitting Diodes. NANO LETTERS 2022; 22:9500-9506. [PMID: 36459088 DOI: 10.1021/acs.nanolett.2c03564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Despite recent rapid advances in improving quantum dot light-emitting diodes, many fundamental aspects of the device operating mechanism remain unresolved. Through transient electroluminescence and time-resolved photoluminescence measurements, the effects of offset voltage on charging and charge transport are examined. First, capacitive charging occurs with a time constant of ∼500 ns, followed by electron transport through quantum dots with a mobility of ∼10-5 cm2 V-1 s-1. Hole injection then initiates an electroluminescence rise that is independent of offset voltage. The photoluminescence lifetime is also unaffected by the offset voltage, indicating no injection of charges into the quantum dots or on their surfaces prior to the voltage pulse. A slower equilibration to steady-state electroluminescence is dependent on the offset voltage, indicative of another charging process. Elemental mapping shows that ZnO deposition from solution can lead to the diffusion of charged species into the quantum dot layer, which may cause the slower process.
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Affiliation(s)
- Logan P Keating
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
| | - Hyunho Lee
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
| | - Steven P Rogers
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
| | - Conan Huang
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
| | - Moonsub Shim
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
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Abstract
Anisotropic heterostructures of colloidal nanocrystals embed size-, shape-, and composition-dependent electronic structure within variable three-dimensional morphology, enabling intricate design of solution-processable materials with high performance and programmable functionality. The key to designing and synthesizing such complex materials lies in understanding the fundamental thermodynamic and kinetic factors that govern nanocrystal growth. In this review, nanorod heterostructures, the simplest of anisotropic nanocrystal heterostructures, are discussed with respect to their growth mechanisms. The effects of crystal structure, surface faceting/energies, lattice strain, ligand sterics, precursor reactivity, and reaction temperature on the growth of nanorod heterostructures through heteroepitaxy and cation exchange reactions are explored with currently known examples. Understanding the role of various thermodynamic and kinetic parameters enables the controlled synthesis of complex nanorod heterostructures that can exhibit unique tailored properties. Selected application prospects arising from such capabilities are then discussed.
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Affiliation(s)
- Gryphon A Drake
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 United States
| | - Logan P Keating
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 United States
| | - Moonsub Shim
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 United States
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Mallem K, Prodanov MF, Dezhang C, Marus M, Kang C, Shivarudraiah SB, Vashchenko VV, Halpert JE, Srivastava AK. Solution-Processed Red, Green, and Blue Quantum Rod Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2022; 14:18723-18735. [PMID: 35417119 DOI: 10.1021/acsami.2c04466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Solution-processed semiconductor nanocrystals are evolving as potential candidates for future display and lighting applications owing to their size-tunable emission, ultrasaturated colors, and compatibility with large-area flexible substrates. Among them, quantum rods (QRs) are emerging materials for optoelectronic applications, offering polarized emission, high light outcoupling efficiency, color purity, and better stability in solid films. However, synthesizing QRs covering the full visible wavelength region has been a big challenge, particularly in the blue range. Herein, we report for the first time the synthesis of red CdSe/CdS, green CdSe/ZnxCd1-xS/ZnS, and blue CdSe/ZnxCd1-xS/ZnS QRs and their application in red, green, and blue QR-based light-emitting diodes (QR-LEDs). We have improved the charge injection balance into the QRs through embedding a poly(methyl methacrylate) (PMMA) layer between the emissive and electron transport layers. The thin PMMA electron-blocking layer (EBL) suppresses the excessive electron flux and thus promotes charge injection balance and pushes the recombination zone back to the QR layer, resulting in 1.35×, 1.2×, and 1.7× peak external quantum efficiency improvement for red, green, and blue QR-LEDs, respectively. The efficiency roll-off of green and blue QR-LEDs with an EBL is less than 50% at maximum current density. The proposed red, green, and blue QR-LEDs open up an avenue toward further improving the light source efficiency and stability focusing on real device applications.
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Affiliation(s)
- Kumar Mallem
- State Key Laboratory on Advanced Displays and Optoelectronics Technologies and Centre for Display Research, Department of Electronics and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
| | - Maksym F Prodanov
- State Key Laboratory on Advanced Displays and Optoelectronics Technologies and Centre for Display Research, Department of Electronics and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
| | - Chen Dezhang
- Department of Chemistry, Hong Kong University of Science and Technology (HKUST), Clear Water Bay Road, Kowloon, Hong Kong 999077, China
| | - Mikita Marus
- State Key Laboratory on Advanced Displays and Optoelectronics Technologies and Centre for Display Research, Department of Electronics and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
| | - Chengbin Kang
- State Key Laboratory on Advanced Displays and Optoelectronics Technologies and Centre for Display Research, Department of Electronics and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
| | - Sunil B Shivarudraiah
- Department of Chemistry, Hong Kong University of Science and Technology (HKUST), Clear Water Bay Road, Kowloon, Hong Kong 999077, China
| | - Valeri V Vashchenko
- State Key Laboratory on Advanced Displays and Optoelectronics Technologies and Centre for Display Research, Department of Electronics and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
| | - Jonathan E Halpert
- Department of Chemistry, Hong Kong University of Science and Technology (HKUST), Clear Water Bay Road, Kowloon, Hong Kong 999077, China
| | - Abhishek K Srivastava
- State Key Laboratory on Advanced Displays and Optoelectronics Technologies and Centre for Display Research, Department of Electronics and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
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11
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Cui J, Liu Y, Deng Y, Lin C, Fang Z, Xiang C, Bai P, Du K, Zuo X, Wen K, Gong S, He H, Ye Z, Gao Y, Tian H, Zhao B, Wang J, Jin Y. Efficient light-emitting diodes based on oriented perovskite nanoplatelets. SCIENCE ADVANCES 2021; 7:eabg8458. [PMID: 34623917 PMCID: PMC8500509 DOI: 10.1126/sciadv.abg8458] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Solution-processed planar perovskite light-emitting diodes (LEDs) promise high-performance and cost-effective electroluminescent devices ideal for large-area display and lighting applications. Exploiting emission layers with high ratios of horizontal transition dipole moments (TDMs) is expected to boost the photon outcoupling of planar LEDs. However, LEDs based on anisotropic perovskite nanoemitters remain to be inefficient (external quantum efficiency, EQE <5%) due to the difficulties of simultaneously controlling the orientations of TDMs, achieving high photoluminescence quantum yields (PLQYs) and realizing charge balance in the films of assembled nanostructures. Here, we demonstrate efficient electroluminescence from an in situ grown perovskite film composed of a monolayer of face-on oriented nanoplatelets. The ratio of horizontal TDMs of the perovskite nanoplatelet film is ~84%, which leads to a light-outcoupling efficiency of ~31%, substantially higher than that of isotropic emitters (~23%). In consequence, LEDs with a peak EQE of 23.6% are achieved, representing highly efficient planar perovskite LEDs.
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Affiliation(s)
- Jieyuan Cui
- Zhejiang Key Laboratory for Excited-State Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yang Liu
- Zhejiang Key Laboratory for Excited-State Materials, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yunzhou Deng
- Zhejiang Key Laboratory for Excited-State Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Chen Lin
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhishan Fang
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Chensheng Xiang
- Centre of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Peng Bai
- China State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Kai Du
- Centre of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Xiaobing Zuo
- X-Ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Kaichuan Wen
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Centre for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Shaolong Gong
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, China
| | - Haiping He
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhizhen Ye
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
- ZJU-WZ Novel Materials Science & Technology Innovation Center, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, China
- Corresponding author. (Z.Y.); (Y.J.)
| | - Yunan Gao
- China State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - He Tian
- Centre of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Baodan Zhao
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310027, China
| | - Jianpu Wang
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Centre for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Yizheng Jin
- Zhejiang Key Laboratory for Excited-State Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
- Corresponding author. (Z.Y.); (Y.J.)
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Rhee S, Jung D, Kim D, Lee DC, Lee C, Roh J. Polarized Electroluminescence Emission in High-Performance Quantum Rod Light-Emitting Diodes via the Langmuir-Blodgett Technique. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2101204. [PMID: 34242488 DOI: 10.1002/smll.202101204] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 05/30/2021] [Indexed: 06/13/2023]
Abstract
Due to their anisotropic structure, quantum rods (QRs) feature unique properties that differ from quantum dots, such as suppression of non-radiative Auger recombination and linearly polarized light emission. Despite many potential advantages, the progress of QR-based light-emitting diodes (QR-LEDs) is left behind due to the difficulty in aligning QRs. In this study, polarized electroluminescence emission is reported in high-performance QR-LEDs by employing the Langmuir-Blodgett (LB) technique. The adoption of the LB technique successfully produces a highly dense and smooth QR film with a high degree of alignment. As a result, the aligned QR films exhibit polarized photoluminescence emission with a degree of linear polarization of 2.1. Advantageous features of the LB technique, such as nondestructiveness, precise thickness control, and the nonnecessity of an additional matrix material, allow to fabricate QR-LEDs with the same procedure as the standard spin coating-based scheme. The device is fabricated via the LB technique, which shows excellent device performance, such as the low turn-on voltage of 1.8 V, peak luminance of 56 287 cd m-2 , and peak external quantum efficiency (EQE) of 10.33%. Furthermore, these devices clearly exhibit an indication of polarized electroluminescence emission, which opens new opportunities for QRs in display technologies.
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Affiliation(s)
- Seunghyun Rhee
- SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Electrical Engineering and Computer Science, Inter-University Semiconductor Research Center (ISRC), Seoul National University, Seoul, 08826, Republic of Korea
| | - Dongju Jung
- SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Dahin Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Doh C Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Changhee Lee
- Department of Electrical Engineering and Computer Science, Inter-University Semiconductor Research Center (ISRC), Seoul National University, Seoul, 08826, Republic of Korea
| | - Jeongkyun Roh
- Department of Electrical Engineering, Pusan National University, Busan, 46241, Republic of Korea
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13
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Zhang C, Chen J, Wang S, Kong L, Lewis SW, Yang X, Rogach AL, Jia G. Metal Halide Perovskite Nanorods: Shape Matters. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002736. [PMID: 32985008 DOI: 10.1002/adma.202002736] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/05/2020] [Indexed: 05/22/2023]
Abstract
Quasi-1D metal halide perovskite nanorods (NRs) are emerging as a type of materials with remarkable optical and electronic properties. Research into this field is rapidly expanding and growing in the past several years, with significant advances in both mechanistic studies of their growth and widespread possible applications. Here, the recent advances in 1D metal halide perovskite nanocrystals (NCs) are reviewed, with a particular emphasis on NRs. At first, the crystal structures of perovskites are elaborated, which is followed by a review of the major synthetic approaches toward perovskite NRs, such as wet-chemical synthesis, substrate-assisted growth, and anion exchange reactions, and discussion of the growth mechanisms associated with each synthetic method. Then, thermal and aqueous stability and the linear polarized luminescence of perovskite NRs are considered, followed by highlighting their applications in solar cells, light-emitting diodes, photodetectors/phototransistors, and lasers. Finally, challenges and future opportunities in this rapidly developing research area are summarized.
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Affiliation(s)
- Chengxi Zhang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai, 200072, P. R. China
| | - Jiayi Chen
- Curtin Institute of Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Sheng Wang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai, 200072, P. R. China
| | - Lingmei Kong
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai, 200072, P. R. China
| | - Simon W Lewis
- Curtin Institute of Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Xuyong Yang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai, 200072, P. R. China
| | - Andrey L Rogach
- Department of Materials Science and Engineering & Centre for Functional Photonics (CFP) City University of Hong Kong, Kowloon, Hong Kong SAR, P. R. China
| | - Guohua Jia
- Curtin Institute of Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
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14
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Yu Y, Zhuo MP, Chen S, He GP, Tao YC, Wang XD, Liao LS. Molecular- and Structural-Level Organic Heterostructures for Multicolor Photon Transportation. J Phys Chem Lett 2020; 11:7517-7524. [PMID: 32813531 DOI: 10.1021/acs.jpclett.0c02293] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The rational design and the fine synthesis of organic heterostructures (OHSs) are the key steps toward integrated organic optoelectronics. Herein we have demonstrated a self-assembly approach of combining a molecular-level heterostructure with a structural-level heterostructure and regulating the noncovalent intermolecular interactions for the precise construction of OHSs: a vertical type of anthracene-TCNB heterostructure and a horizontal type of benzopyrene-TCNB heterostructure. The excellent structural compatibility and the low lattice mismatch rate of ∼5.8% between single-component microplates and cocrystal microwires allow anthracene and benzopyrene molecules to grow epitaxially on the cocrystal. Significantly, integrating the multicolor emission and the distinctive dimensional-dependent photon transportation properties of low-dimensional micro/nanostructures, the multicolor optical outputs are achieved via modulating the active/passive optical waveguides in OHSs. Our work exhibits the utilization of the multilevel heterostructure strategy, which boosts the rational design of OHSs for organic photonics.
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Affiliation(s)
- Yue Yu
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Ming-Peng Zhuo
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Song Chen
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Guang-Peng He
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Yi-Chen Tao
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Xue-Dong Wang
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Liang-Sheng Liao
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China
- Institute of Organic Optoelectronics, Jiangsu Industrial Technology Research Institute (JITRI), Wujiang, Suzhou, Jiangsu 215211, P. R. China
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15
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Wang R, Guo M, Hu Y, Zhou J, Wu R, Yang X. A Molecularly Imprinted Fluorescence Sensor Based on the ZnO Quantum Dot Core-Shell Structure for High Selectivity and Photolysis Function of Methylene Blue. ACS OMEGA 2020; 5:20664-20673. [PMID: 32832820 PMCID: PMC7439697 DOI: 10.1021/acsomega.0c03095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
ZnO quantum dots and CuFe2O4 nanoparticles were synthesized by chemical precipitation. The ZCF composite was created by the solvothermal method. A new molecularly imprinted fluorescence sensor (ZCF@MB-MIP) with unique optical properties and specific MB recognition was successfully generated. ZCF@MB-MIPs were characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and X-ray diffraction and were applied for the selective detection of methylene blue (MB). The optimal working time of ZCF@MB-MIPs was 15 min, and the optimal working concentration was 37 mg·L-1. The fluorescence intensity was linearly quenched within the 0-100 μmol·L-1 MB range, and the detection limit was 1.27 μmol·L-1. The imprinting factor of the sensor (IF, K MB-MIPs/N-MIPs) was 5.30. At the same time, a real-time monitoring system was established for the photodegradation process of MB, which had the effect of reflecting the degradation degree of MB at any given time. Hence, ZCF@MB-MIPs are a promising candidate for use in MB monitoring, and they also provides a new strategy for constructing a multifunctional fluorescence sensor with a high selectivity and photolysis function.
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Affiliation(s)
- Rui Wang
- College
of Engineering, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
| | - Ming Guo
- College
of Engineering, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
- Department
of Chemistry, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
| | - Yinglu Hu
- College
of Engineering, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
| | - Jianhai Zhou
- Department
of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Ronghui Wu
- Department
of Chemistry, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
| | - Xuejuan Yang
- Department
of Chemistry, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China
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16
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Shcherbakov-Wu W, Tisdale WA. A time-domain view of charge carriers in semiconductor nanocrystal solids. Chem Sci 2020; 11:5157-5167. [PMID: 34122972 PMCID: PMC8159276 DOI: 10.1039/c9sc05925c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 04/29/2020] [Indexed: 01/12/2023] Open
Abstract
The movement of charge carriers within semiconductor nanocrystal solids is fundamental to the operation of nanocrystal devices, including solar cells, LEDs, lasers, photodetectors, and thermoelectric modules. In this perspective, we explain how recent advances in the measurement and simulation of charge carrier dynamics in nanocrystal solids have led to a more complete picture of mesoscale interactions. Specifically, we show how time-resolved optical spectroscopy and transient photocurrent techniques can be used to track both equilibrium and non-equilibrium dynamics in nanocrystal solids. We discuss the central role of energetic disorder, the impact of trap states, and how these critical parameters are influenced by chemical modification of the nanocrystal surface. Finally, we close with a forward-looking assessment of emerging nanocrystal systems, including anisotropic nanocrystals, such as nanoplatelets, and colloidal lead halide perovskites.
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Affiliation(s)
- Wenbi Shcherbakov-Wu
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - William A Tisdale
- Department of Chemical Engineering, Massachusetts Institute of Technology Cambridge MA 02139 USA
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17
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Lee H, Yoon DE, Koh S, Kang MS, Lim J, Lee DC. Ligands as a universal molecular toolkit in synthesis and assembly of semiconductor nanocrystals. Chem Sci 2020; 11:2318-2329. [PMID: 32206291 PMCID: PMC7069383 DOI: 10.1039/c9sc05200c] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 02/10/2020] [Indexed: 01/05/2023] Open
Abstract
The multiple ligands with different functionalities enable atomic-precision control of NCs morphology and subtle inter-NC interactions, which paves the way for novel optoelectronic applications.
Successful exploitation of semiconductor nanocrystals (NCs) in commercial products is due to the remarkable progress in the wet-chemical synthesis and controlled assembly of NCs. Central to the cadence of this progress is the ability to understand how NC growth and assembly can be controlled kinetically and thermodynamically. The arrested precipitation strategy offers a wide opportunity for materials selection, size uniformity, and morphology control. In this colloidal approach, capping ligands play an instrumental role in determining growth parameters and inter-NC interactions. The impetus for exquisite control over the size and shape of NCs and orientation of NCs in an ensemble has called for the use of two or more types of ligands in the system. In multiple ligand approaches, ligands with different functionalities confer extended tunability, hinting at the possibility of atomic-precision growth and long-range ordering of desired superlattices. Here, we highlight the progress in understanding the roles of ligands in size and shape control and assembly of NCs. We discuss the implication of the advances in the context of optoelectronic applications.
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Affiliation(s)
- Hyeonjun Lee
- Department of Chemical and Biomolecular Engineering , KAIST Institute for the Nanocentury , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea .
| | - Da-Eun Yoon
- Department of Chemical and Biomolecular Engineering , KAIST Institute for the Nanocentury , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea .
| | - Sungjun Koh
- Department of Chemical and Biomolecular Engineering , KAIST Institute for the Nanocentury , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea .
| | - Moon Sung Kang
- Department of Chemical and Biomolecular Engineering , Sogang University , Seoul 04107 , Republic of Korea
| | - Jaehoon Lim
- Department of Energy Science , Center for Artificial Atoms , Sungkyunkwan University (SKKU) , Suwon , Gyeonggi-do 16419 , Republic of Korea .
| | - Doh C Lee
- Department of Chemical and Biomolecular Engineering , KAIST Institute for the Nanocentury , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea .
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18
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Kelestemur Y, Shynkarenko Y, Anni M, Yakunin S, De Giorgi ML, Kovalenko MV. Colloidal CdSe Quantum Wells with Graded Shell Composition for Low-Threshold Amplified Spontaneous Emission and Highly Efficient Electroluminescence. ACS NANO 2019; 13:13899-13909. [PMID: 31769648 DOI: 10.1021/acsnano.9b05313] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Semiconductor nanoplatelets (NPLs) have emerged as a very promising class of colloidal nanocrystals for light-emitting devices owing to their quantum-well-like electronic and optical characteristics. However, their lower photoluminescence quantum yield (PLQY) and limited stability have hampered the realization of their outstanding luminescent properties in device applications. Here, to address these deficiencies, we present a two-step synthetic approach that enables the synthesis of core/shell NPLs with precisely controlled shell composition for engineering their excitonic properties. The proposed CdSe colloidal quantum wells possess a graded shell, which is composed of a CdS buffer layer and a CdxZn1-xS gradient layer, and exhibit bright emission (PLQY 75-89%) in the red spectral region (634-648 nm) with a narrow emission line width (21 nm). These enhanced optical properties allowed us to attain low thresholds for amplified spontaneous emission (down to ∼40 μJ/cm2) under nanosecond laser excitation. We also studied the electroluminescent performance of these NPLs by fabricating solution-processed light-emitting diodes (LEDs). In comparison to NPL-LEDs with CdSe/CdS core/shell NPLs, which exhibit an external quantum efficiency (EQE) value of only 1.80%, a significantly improved EQE value of 9.92% was obtained using graded-shell NPLs, the highest value for colloidal NPL-based-LEDs. In addition, the low efficiency roll-off characteristics of NPL-LEDs enabled a high brightness of up to ∼46 000 cd/m2 with an electroluminescence peak centered at 650 nm. These findings demonstrate the paramount role that heterostructure engineering occupies in enhancing the optoelectronic characteristics of semiconductor NPLs toward practically relevant levels.
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Affiliation(s)
- Yusuf Kelestemur
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir Prelog Weg 1 , CH-8093 Zürich , Switzerland
- Empa-Swiss Federal Laboratories for Materials Science and Technology , Überlandstrasse 129 , CH-8600 Dübendorf , Switzerland
| | - Yevhen Shynkarenko
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir Prelog Weg 1 , CH-8093 Zürich , Switzerland
- Empa-Swiss Federal Laboratories for Materials Science and Technology , Überlandstrasse 129 , CH-8600 Dübendorf , Switzerland
| | - Marco Anni
- Dipartimento di Matematica e Fisica "Ennio De Giorgi" , Università del Salento , Via per Arnesano , 73100 Lecce , Italy
| | - Sergii Yakunin
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir Prelog Weg 1 , CH-8093 Zürich , Switzerland
- Empa-Swiss Federal Laboratories for Materials Science and Technology , Überlandstrasse 129 , CH-8600 Dübendorf , Switzerland
| | - Maria Luisa De Giorgi
- Dipartimento di Matematica e Fisica "Ennio De Giorgi" , Università del Salento , Via per Arnesano , 73100 Lecce , Italy
| | - Maksym V Kovalenko
- Department of Chemistry and Applied Biosciences , ETH Zürich , Vladimir Prelog Weg 1 , CH-8093 Zürich , Switzerland
- Empa-Swiss Federal Laboratories for Materials Science and Technology , Überlandstrasse 129 , CH-8600 Dübendorf , Switzerland
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19
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Cao L, Liu X, Guo Z, Zhou L. Surface/Interface Engineering for Constructing Advanced Nanostructured Light-Emitting Diodes with Improved Performance: A Brief Review. MICROMACHINES 2019; 10:E821. [PMID: 31783596 PMCID: PMC6953049 DOI: 10.3390/mi10120821] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 01/30/2023]
Abstract
With the rise of nanoscience and nanotechnologies, especially the continuous deepening of research on low-dimensional materials and structures, various kinds of light-emitting devices based on nanometer-structured materials are gradually becoming the natural candidates for the next generation of advanced optoelectronic devices with improved performance through engineering their interface/surface properties. As dimensions of light-emitting devices are scaled down to the nanoscale, the plentitude of their surface/interface properties is one of the key factors for their dominating device performance. In this paper, firstly, the generation, classification, and influence of surface/interface states on nanometer optical devices will be given theoretically. Secondly, the relationship between the surface/interface properties and light-emitting diode device performance will be investigated, and the related physical mechanisms will be revealed by introducing classic examples. Especially, how to improve the performance of light-emitting diodes by using factors such as the surface/interface purification, quantum dots (QDs)-emitting layer, surface ligands, optimization of device architecture, and so on will be summarized. Finally, we explore the main influencing actors of research breakthroughs related to the surface/interface properties on the current and future applications for nanostructured light-emitting devices.
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Affiliation(s)
- Lianzhen Cao
- Department of Physics and Optoelectronic Engineering, Weifang University, Weifang 261061, China;
- CASKey Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Xia Liu
- Department of Physics and Optoelectronic Engineering, Weifang University, Weifang 261061, China;
- CASKey Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Zhen Guo
- CASKey Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
- Shandong Guo Ke Medical Technology Development Co., Ltd., Jinan 25001, China
- Zhongke Mass Spectrometry (Tianjin) Medical Technology Co., Ltd. Tianjin 300399, China
| | - Lianqun Zhou
- CASKey Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
- Jihua Laboratory, Foshan 528200, China
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20
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Seok HJ, Kang YJ, Kim J, Kim DH, Heo SB, Kang SJ, Kim HK. Tetrahedral amorphous carbon prepared filter cathodic vacuum arc for hole transport layers in perovskite solar cells and quantum dots LEDs. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2019; 20:1118-1130. [PMID: 32002086 PMCID: PMC6968577 DOI: 10.1080/14686996.2019.1694841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 06/10/2023]
Abstract
(ta-C) films coated through the filtered cathodic vacuum arc (FCVA) process as a hole transport layer (HTL) for perovskite solar cells (PSCs) and quantum dot light-emitting diodes (QDLEDs). The p-type ta-C film has several remarkable features, including ease of fabrication without the need for thermal annealing, reasonable electrical conductivity, optical transmittance, and a high work function. X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy examinations show that the electrical properties (sp3/sp2 hybridized bond) and work function of the ta-C HTL are appropriate for PSCs and QDLEDs. In addition, in order to correlate the performance of the devices, the optical, surface morphological, and structural properties of the FCVA-grown ta-C films with different thicknesses (5 ~ 20 nm) deposited on the ITO anode are investigated in detail. The optimized ta-C film with a thickness of 5 nm deposited on the ITO anode had a sheet resistance of 10.33 Ω-2, a resistivity of 1.34 × 10-4 Ω cm, and an optical transmittance of 88.97%. Compared to the reference PSC with p-NiO HTL, the PSC with 5 nm thick ta-C HTL yielded a higher power conversion efficiency (PCE, 10.53%) due to its improved fill factor. Further, the performance of QDLEDs with 5 nm thick ta-C hole injection layers (HIL) showed better than the performance of QDLEDs with different ta-C thicknesses. It is concluded that ta-C films have the potential to serve as HTL and HIL in next-generation PSCs and QDLEDs.
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Affiliation(s)
- Hae-Jun Seok
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon-si, Republic of Korea
| | - Yong-Jin Kang
- Surface Engineering Department, Implementation Research Division, Korea Institute of Materials Science (KIMS), Changwon-Si, Republic of Korea
| | - Jongkuk Kim
- Surface Engineering Department, Implementation Research Division, Korea Institute of Materials Science (KIMS), Changwon-Si, Republic of Korea
| | - Do-Hyeong Kim
- Energy & New Industry Laboratory, Korea Electric Power Research Institute, Daejeon, Republic of Korea
| | - Su Been Heo
- Department of Advanced Materials Engineering for Information and Electronics, Kyung-Hee University, Yongin-si, Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung-Hee University, Yongin-si, Republic of Korea
| | - Han-Ki Kim
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon-si, Republic of Korea
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21
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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.
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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
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22
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Chen J, Ma Q, Wu XJ, Li L, Liu J, Zhang H. Wet-Chemical Synthesis and Applications of Semiconductor Nanomaterial-Based Epitaxial Heterostructures. NANO-MICRO LETTERS 2019; 11:86. [PMID: 34138028 PMCID: PMC7770813 DOI: 10.1007/s40820-019-0317-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 09/29/2019] [Indexed: 05/19/2023]
Abstract
Semiconductor nanomaterial-based epitaxial heterostructures with precisely controlled compositions and morphologies are of great importance for various applications in optoelectronics, thermoelectrics, and catalysis. Until now, various kinds of epitaxial heterostructures have been constructed. In this minireview, we will first introduce the synthesis of semiconductor nanomaterial-based epitaxial heterostructures by wet-chemical methods. Various architectures based on different kinds of seeds or templates are illustrated, and their growth mechanisms are discussed in detail. Then, the applications of epitaxial heterostructures in optoelectronics, catalysis, and thermoelectrics are described. Finally, we provide some challenges and personal perspectives for the future research directions of semiconductor nanomaterial-based epitaxial heterostructures.
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Affiliation(s)
- Junze Chen
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Qinglang Ma
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Xue-Jun Wu
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, People's Republic of China
| | - Liuxiao Li
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Jiawei Liu
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Hua Zhang
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
- Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong, People's Republic of China.
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Drake GA, Flanagan JC, Shim M. Highly luminescent double-heterojunction nanorods. J Chem Phys 2019; 151:134706. [DOI: 10.1063/1.5121159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Gryphon A. Drake
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, USA
| | - Joseph C. Flanagan
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, USA
| | - Moonsub Shim
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, USA
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24
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Kim H, Lee W, Moon H, Kim SJ, Chung HK, Chae H. Interlayer doping with p-type dopant for charge balance in indium phosphide (InP)-based quantum dot light-emitting diodes. OPTICS EXPRESS 2019; 27:A1287-A1296. [PMID: 31510582 DOI: 10.1364/oe.27.0a1287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 07/14/2019] [Indexed: 06/10/2023]
Abstract
A 2,3,4,6-tetrafluoro-7,7,8,8,-tetracyanoquinodimethane (F4-TCNQ) doping interlayer was developed to improve charge imbalance and the efficiency in indium phosphide (InP)-based quantum dot light-emitting diodes (QLEDs). The doping layer was coated between a hole injecting layer (HIL) and a hole transport layer (HTL) and successfully diffused with thermal annealing. This doping reduces the hole injection barrier and improves the charge balance of InP-based QLEDs, resulting in enhancement of an external quantum efficiency (EQE) of 3.78% (up from 1.6%) and a power efficiency of 6.41 lm/W (up from 2.77 lm/W). This work shows that F4-TCNQ interlayer doping into both HIL and HTL facilitates hole injection and can provide an efficient solution of improving charge balance in QLED for the device efficiency.
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Jia G, Pang Y, Ning J, Banin U, Ji B. Heavy-Metal-Free Colloidal Semiconductor Nanorods: Recent Advances and Future Perspectives. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1900781. [PMID: 31063615 DOI: 10.1002/adma.201900781] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/26/2019] [Indexed: 05/10/2023]
Abstract
Quasi-1D colloidal semiconductor nanorods (NRs) are at the forefront of nanoparticle (NP) research owing to their intriguing size-dependent and shape-dependent optical and electronic properties. The past decade has witnessed significant advances in both fundamental understanding of the growth mechanisms and applications of these stimulating materials. Herein, the state-of-the-art of colloidal semiconductor NRs is reviewed, with special emphasis on heavy-metal-free materials. The main growth mechanisms of heavy-metal-free colloidal semiconductor NRs are first elaborated, including anisotropic-controlled growth, oriented attachment, solution-liquid-solid method, and cation exchange. Then, structural engineering and properties of semiconductor NRs are discussed, with a comprehensive overview of core/shell structures, alloying, and doping, as well as semiconductor-metal hybrid nanostructures, followed by highlighted practical applications in terms of photocatalysis, photodetectors, solar cells, and biomedicine. Finally, challenges and future opportunities in this fascinating research area are proposed.
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Affiliation(s)
- Guohua Jia
- Curtin Institute of Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, GPO Box U1987, WA, 6845, Australia
| | - Yingping Pang
- Curtin Institute of Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, GPO Box U1987, WA, 6845, Australia
| | - Jiajia Ning
- Department of Materials Science and Engineering & Centre for Functional Photonics (CFP), City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Uri Banin
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Botao Ji
- School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, China
- Institute of Advanced Technology Westlake Institute for Advanced Study, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, China
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26
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Lee S, Flanagan JC, Kim J, Yun AJ, Lee B, Shim M, Park B. Efficient Type-II Heterojunction Nanorod Sensitized Solar Cells Realized by Controlled Synthesis of Core/Patchy-Shell Structure and CdS Cosensitization. ACS APPLIED MATERIALS & INTERFACES 2019; 11:19104-19114. [PMID: 31066260 DOI: 10.1021/acsami.9b02873] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Here, we report the successful application of core/patchy-shell CdSe/CdSe xTe1- x type-II heterojunction nanorods (HNRs) to realize efficient sensitized solar cells. The core/patchy-shell structure designed to have a large type-II heterointerface without completely shielding the CdSe core significantly improves photovoltaic performance compared to other HNRs with minimal or full-coverage shells. In addition, cosensitization with CdS grown by successive ionic layer adsorption and reaction further improves the power conversion efficiency. One-diode model analysis reveals that the HNRs having exposed CdSe cores and suitably grown CdS result in significant reduction of series resistance. Investigation of the intercorrelation between diode quality parameters, diode saturation current density ( J0) and recombination order (β = (ideality factor)-1) reveals that HNRs with open CdSe cores exhibit reduced recombination. These results confirm that the superior performance of core/patchy-shell HNRs results from their fine-tuned structure: photocurrent is increased by the large type-II heterointerface and recombination is effectively suppressed due to the open CdSe core enabling facile electron extraction. An optimized power conversion efficiency of 5.47% (5.89% with modified electrode configuration) is reported, which is unmatched among photovoltaics utilizing anisotropic colloidal heterostructures as light-harvesting materials.
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Affiliation(s)
- Sangheon Lee
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials , Seoul National University , Seoul 08226 , Korea
| | - Joseph C Flanagan
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Jaewook Kim
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials , Seoul National University , Seoul 08226 , Korea
| | - Alan Jiwan Yun
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials , Seoul National University , Seoul 08226 , Korea
| | - Byungho Lee
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials , Seoul National University , Seoul 08226 , Korea
| | - Moonsub Shim
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Byungwoo Park
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials , Seoul National University , Seoul 08226 , Korea
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27
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Lova P, Giusto P, Di Stasio F, Manfredi G, Paternò GM, Cortecchia D, Soci C, Comoretto D. All-polymer methylammonium lead iodide perovskite microcavities. NANOSCALE 2019; 11:8978-8983. [PMID: 31017152 DOI: 10.1039/c9nr01422e] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Thanks to a high photoluminescence quantum yield, large charge carrier diffusion, and ease of processing from solution, perovskite materials are becoming increasingly interesting for flexible optoelectronic devices. However, their deposition requires wide range solvents that are incompatible with many other flexible and solution-processable materials, including polymers. Here, we show that methylammonium lead iodide (MAPbI3) films can be directly synthesized on all-polymer microcavities via simple addition of a perfluorinated layer which protects the polymer photonic structure from the perovskite processing solvents. The new processing provides microcavities with a quality factor Q = 155, that is in agreement with calculations and the largest value reported so far for fully solution processed perovskite microcavities. Furthermore, the obtained microcavity shows strong spectral and angular redistribution of the the MAPbI3 photoluminescence spectrum, which shows a 3.5 fold enhanced intensity with respect to the detuned reference. The opportunity to control and modify the emission of a MAPbI3 film via a simple spun-cast polymer structure is of great interest in advanced optoelectronic applications requiring high colour purity or emission directionality.
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Affiliation(s)
- Paola Lova
- Dipartimento di Chimica e Chimica Industriale, Università di Genova, 16146 Genova, Italy.
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Jiang Y, Jiang L, Yan Yeung FS, Xu P, Chen S, Kwok HS, Li G. All-Inorganic Quantum-Dot Light-Emitting Diodes with Reduced Exciton Quenching by a MgO Decorated Inorganic Hole Transport Layer. ACS APPLIED MATERIALS & INTERFACES 2019; 11:11119-11124. [PMID: 30874422 DOI: 10.1021/acsami.9b01742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Here, wide-bandgap magnesium oxide (MgO) is employed as a decorator for the nickel oxide (NiO x) hole transport layer (HTL), by means of a bulk dopant as well as a surface modifier. QLEDs with Ni0.88Mg0.12O x serving as the HTL achieve an ∼19.5% efficiency improvement compared to devices using pristine NiO x. Further inserting an ultrathin MgO layer between the Ni0.88Mg0.12O x and QDs to separate the accumulated charges from excitons goes on boosting the peak efficiency by another ∼35%. Finally, a maximum brightness over 40 000 cd/m2 at 10 V is obtained, which is the highest among the reported values.
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Affiliation(s)
- Yibin Jiang
- State Key Lab on Advanced Displays and Optoelectronics , The Hong Kong University of Science & Technology , Clear Water Bay , Kowloon , Hong Kong
| | - Le Jiang
- College of Electronic Science and Technology , Shenzhen University , Shenzhen , 518060 , P.R. China
| | - Fion Sze Yan Yeung
- State Key Lab on Advanced Displays and Optoelectronics , The Hong Kong University of Science & Technology , Clear Water Bay , Kowloon , Hong Kong
| | - Ping Xu
- College of Electronic Science and Technology , Shenzhen University , Shenzhen , 518060 , P.R. China
| | - Shuming Chen
- Department of Electrical and Electronic Engineering , Southern University of Science and Technology , Shenzhen , 518055 , P. R. China
| | - Hoi-Sing Kwok
- State Key Lab on Advanced Displays and Optoelectronics , The Hong Kong University of Science & Technology , Clear Water Bay , Kowloon , Hong Kong
| | - Guijun Li
- College of Electronic Science and Technology , Shenzhen University , Shenzhen , 518060 , P.R. China
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29
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Zhang Y, Zhang F, Wang H, Wang L, Wang F, Lin Q, Shen H, Li LS. High-efficiency CdSe/CdS nanorod-based red light-emitting diodes. OPTICS EXPRESS 2019; 27:7935-7944. [PMID: 31052619 DOI: 10.1364/oe.27.007935] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 02/28/2019] [Indexed: 06/09/2023]
Abstract
In this paper, we report the synthesis, the structural and optical characterization of CdSe/CdS//CdS nanorods (NRs) and their exploitation in nanorod-based light-emitting diodes (NR-LEDs). Two kinds of NRs of CdSe/CdS and CdSe/CdS//CdS were incorporated into the structure of solution-processed hybrid NR-LEDs. Compared to CdSe/CdS, the efficiencies of CdSe/CdS//CdS NR-based LEDs are overwhelmingly higher, specifically showing unprecedented values of peak current efficiency of 19.8 cd/A and external quantum efficiency of 15.7%. Such excellent results are likely attributable to a unique structure in CdSe/CdS//CdS NRs with a relatively high quantum yield, thick CdS outer shell, and rod structure which minimize nonradiative energy transfer between closely packed NRs in emitting layer.
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30
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Bai X, Purcell-Milton F, Gun'ko YK. Optical Properties, Synthesis, and Potential Applications of Cu-Based Ternary or Quaternary Anisotropic Quantum Dots, Polytypic Nanocrystals, and Core/Shell Heterostructures. NANOMATERIALS 2019; 9:nano9010085. [PMID: 30634642 PMCID: PMC6359286 DOI: 10.3390/nano9010085] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 12/28/2018] [Accepted: 12/31/2018] [Indexed: 12/29/2022]
Abstract
This review summaries the optical properties, recent progress in synthesis, and a range of applications of luminescent Cu-based ternary or quaternary quantum dots (QDs). We first present the unique optical properties of the Cu-based multicomponent QDs, regarding their emission mechanism, high photoluminescent quantum yields (PLQYs), size-dependent bandgap, composition-dependent bandgap, broad emission range, large Stokes’ shift, and long photoluminescent (PL) lifetimes. Huge progress has taken place in this area over the past years, via detailed experimenting and modelling, giving a much more complete understanding of these nanomaterials and enabling the means to control and therefore take full advantage of their important properties. We then fully explore the techniques to prepare the various types of Cu-based ternary or quaternary QDs (including anisotropic nanocrystals (NCs), polytypic NCs, and spherical, nanorod and tetrapod core/shell heterostructures) are introduced in subsequent sections. To date, various strategies have been employed to understand and control the QDs distinct and new morphologies, with the recent development of Cu-based nanorod and tetrapod structure synthesis highlighted. Next, we summarize a series of applications of these luminescent Cu-based anisotropic and core/shell heterostructures, covering luminescent solar concentrators (LSCs), bioimaging and light emitting diodes (LEDs). Finally, we provide perspectives on the overall current status, challenges, and future directions in this field. The confluence of advances in the synthesis, properties, and applications of these Cu-based QDs presents an important opportunity to a wide-range of fields and this piece gives the reader the knowledge to grasp these exciting developments.
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Affiliation(s)
- Xue Bai
- School of Chemistry and CRANN Institute, Trinity College Dublin, Dublin 2, Dublin, Ireland.
| | - Finn Purcell-Milton
- School of Chemistry and CRANN Institute, Trinity College Dublin, Dublin 2, Dublin, Ireland.
| | - Yuri K Gun'ko
- School of Chemistry and CRANN Institute, Trinity College Dublin, Dublin 2, Dublin, Ireland.
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32
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Kumagai K, Uematsu T, Torimoto T, Kuwabata S. Direct surface modification of semiconductor quantum dots with metal–organic frameworks. CrystEngComm 2019. [DOI: 10.1039/c9ce00769e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Robust surface protective materials for luminescent semiconductor quantum dots (QDs) are demonstrated by using metal–organic frameworks (MOFs) through a direct link between them.
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Affiliation(s)
- Kohei Kumagai
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
| | - Taro Uematsu
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
| | - Tsukasa Torimoto
- Department of Crystalline Materials Science
- Graduate School of Engineering
- Nagoya University
- Chikusa-ku
- Japan
| | - Susumu Kuwabata
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
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33
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Keum H, Jiang Y, Park JK, Flanagan JC, Shim M, Kim S. Photoresist Contact Patterning of Quantum Dot Films. ACS NANO 2018; 12:10024-10031. [PMID: 30247027 DOI: 10.1021/acsnano.8b04462] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Scalable and cost-effective protocols to pattern and integrate colloidal quantum dots (QDs) with high resolution have been challenging to establish. While their solubility can facilitate certain processes such as spin-casting into thin films, it also makes them incompatible with many conventional patterning techniques including photolithography that require solution processing. In this work, we present "photoresist (PR) contact patterning", a dry means to pattern QD films over large areas with high resolution while maintaining desired properties. Here, a PR layer on an elastomer substrate is patterned by conventional photolithography and used as a dry contact stamp to selectively peel off QDs in the contact regions, leaving behind a QD film with the negative of the PR pattern. Once patterned, QD films are readily transferred and integrated on foreign substrates by subsequent transfer printing processes. Patterned PR layers can also be transferred from elastomer substrates onto QD films and used as masking layers for subsequent deposition and patterning of additional materials, e. g., patterned metal electrodes or charge transport layers for QD-based devices. The study of the interfacial mechanics and energy of materials associated with PR contact patterning reveals why a lithographically patterned PR is superior for high-resolution QD film patterning. Applicability of PR contact patterning is demonstrated through the fabrication of red, green, and blue (RGB) QD light-emitting diode pixels. PR contact patterning presented in this work not only allows dry patterning of QD films but also enables high-resolution integration of functional multistack structures for future QD-based electronic and optoelectronic devices.
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Affiliation(s)
- Hohyun Keum
- Department of Mechanical Science and Engineering , University of Illinois , Urbana , Illinois 61801 , United States
| | - Yiran Jiang
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory , University of Illinois , Urbana , Illinois 61801 , United States
| | - Jun Kyu Park
- Department of Mechanical Science and Engineering , University of Illinois , Urbana , Illinois 61801 , United States
| | - Joseph C Flanagan
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory , University of Illinois , Urbana , Illinois 61801 , United States
| | - Moonsub Shim
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory , University of Illinois , Urbana , Illinois 61801 , United States
| | - Seok Kim
- Department of Mechanical Science and Engineering , University of Illinois , Urbana , Illinois 61801 , United States
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Chen L, Wang S, Li D, Fang Y, Shen H, Li L, Du Z. Simultaneous Improvement of Efficiency and Lifetime of Quantum Dot Light-Emitting Diodes with a Bilayer Hole Injection Layer Consisting of PEDOT:PSS and Solution-Processed WO 3. ACS APPLIED MATERIALS & INTERFACES 2018; 10:24232-24241. [PMID: 29943572 DOI: 10.1021/acsami.8b00770] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Even though chemically stable metal oxides (MOs), as substitutes for poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), have been successfully adopted for improving device stability in solution-processed quantum dot light-emitting diodes (QLEDs), the efficiencies of QLEDs are at a relatively low level. In this work, a novel architecture of QLEDs has been introduced, in which inorganic/organic bilayer hole injection layers (HILs) were delicately designed by inserting an amorphous WO3 interlayer between PEDOT:PSS and the indium tin oxide anode. As a result, the efficiency and operational lifetime of QLEDs were improved simultaneously. The results show that the novel architecture QLEDs relative to conventional PEDOT:PSS-based QLEDs have an enhanced external quantum efficiency by a factor of 50%, increasing from 8.31 to 12.47%, meanwhile exhibit a relatively long operational lifetime (12 551 h) and high maximum brightness (>40 000 cd m-2) resulting from a better pathway for hole injection with staircase energy-level alignment of the HILs and reduction of surface roughness. Our results demonstrate that the novel architecture QLEDs using bilayer MO/PEDOT:PSS HILs can achieve long operational lifetime without sacrificing efficiency.
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Affiliation(s)
- Ling Chen
- Key Laboratory for Special Functional Materials, Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng 475004 , P. R. China
| | - Shujie Wang
- Key Laboratory for Special Functional Materials, Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng 475004 , P. R. China
| | - Dongdong Li
- Key Laboratory for Special Functional Materials, Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng 475004 , P. R. China
| | - Yan Fang
- Key Laboratory for Special Functional Materials, Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng 475004 , P. R. China
| | - Huaibin Shen
- Key Laboratory for Special Functional Materials, Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng 475004 , P. R. China
| | - Linsong Li
- Key Laboratory for Special Functional Materials, Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng 475004 , P. R. China
| | - Zuliang Du
- Key Laboratory for Special Functional Materials, Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng 475004 , P. R. China
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Zhang Z, Ye Y, Pu C, Deng Y, Dai X, Chen X, Chen D, Zheng X, Gao Y, Fang W, Peng X, Jin Y. High-Performance, Solution-Processed, and Insulating-Layer-Free Light-Emitting Diodes Based on Colloidal Quantum Dots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801387. [PMID: 29808563 DOI: 10.1002/adma.201801387] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/08/2018] [Indexed: 05/12/2023]
Abstract
Quantum-dot light-emitting diodes (QLEDs) may combine superior properties of colloidal quantum dots (QDs) and advantages of solution-based fabrication techniques to realize high-performance, large-area, and low-cost electroluminescence devices. In the state-of-the-art red QLED, an ultrathin insulating layer inserted between the QD layer and the oxide electron-transporting layer (ETL) is crucial for both optimizing charge balance and preserving the QDs' emissive properties. However, this key insulating layer demands very accurate and precise control over thicknesses at sub-10 nm level, causing substantial difficulties for industrial production. Here, it is reported that interfacial exciton quenching and charge balance can be independently controlled and optimized, leading to devices with efficiency and lifetime comparable to those of state-of-the-art devices. Suppressing exciton quenching at the ETL-QD interface, which is identified as being obligatory for high-performance devices, is achieved by adopting Zn0.9 Mg0.1 O nanocrystals, instead of ZnO nanocrystals, as ETLs. Optimizing charge balance is readily addressed by other device engineering approaches, such as controlling the oxide ETL/cathode interface and adjusting the thickness of the oxide ETL. These findings are extended to fabrication of high-efficiency green QLEDs without ultrathin insulating layers. The work may rationalize the design and fabrication of high-performance QLEDs without ultrathin insulating layers, representing a step forward to large-scale production and commercialization.
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Affiliation(s)
- Zhenxing Zhang
- Centre for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Yuxun Ye
- State Key Laboratory of Silicon Materials, Centre for Chemistry of High-Performance & Novel Materials, School of Materials Science and Engineering, Hangzhou, 310027, China
| | - Chaodan Pu
- Centre for Chemistry of High-Performance & Novel Materials, Department of Chemistry, Hangzhou, 310027, China
| | - Yunzhou Deng
- Centre for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Xingliang Dai
- State Key Laboratory of Silicon Materials, Centre for Chemistry of High-Performance & Novel Materials, School of Materials Science and Engineering, Hangzhou, 310027, China
| | - Xiaopeng Chen
- Najing Technology Corporation LTD., Hangzhou, 310052, China
| | - Dong Chen
- Centre for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Xuerong Zheng
- Centre for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
| | - Yuan Gao
- Najing Technology Corporation LTD., Hangzhou, 310052, China
| | - Wei Fang
- Center for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaogang Peng
- Centre for Chemistry of High-Performance & Novel Materials, Department of Chemistry, Hangzhou, 310027, China
- Najing Technology Corporation LTD., Hangzhou, 310052, China
| | - Yizheng Jin
- Centre for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, China
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36
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Giovanella U, Pasini M, Lorenzon M, Galeotti F, Lucchi C, Meinardi F, Luzzati S, Dubertret B, Brovelli S. Efficient Solution-Processed Nanoplatelet-Based Light-Emitting Diodes with High Operational Stability in Air. NANO LETTERS 2018; 18:3441-3448. [PMID: 29722262 DOI: 10.1021/acs.nanolett.8b00456] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Colloidal nanoplatelets (NPLs), owing to their efficient and narrow-band luminescence, are considered as promising candidates for solution-processable light-emitting diodes (LEDs) with ultrahigh color purity. To date, however, the record efficiencies of NPL-LEDs are significantly lower than those of more-investigated devices based on spherical nanocrystals. This is particularly true for red-emitting NPL-LEDs, the best-reported external quantum efficiency (EQE) of which is limited to 0.63% (EQE = 5% for green NPL-LEDs). Here, we address this issue by introducing a charge-regulating layer of a polar and polyelectrolytic polymer specifically engineered with complementary trimethylammonium and phosphonate functionalities that provide high solubility in orthogonal polar media with respect to the NPL active layer, compatibility with the metal cathode, and the ability to control electron injection through the formation of a polarized interface under bias. Through this synergic approach, we achieve EQE = 5.73% at 658 nm (color saturation 98%) in completely solution processed LEDs. Remarkably, exposure to air increases the EQE to 8.39%, exceeding the best reports of red NPL-LEDs by over 1 order of magnitude and setting a new global record for quantum-dot LEDs of any color embedding solution-deposited organic interlayers. Considering the emission quantum yield of the NPLs (40 ± 5%), this value corresponds to a near-unity internal quantum efficiency. Notably, our devices show exceptional operational stability for over 5 h of continuous drive in air with no encapsulation, thus confirming the potential of NPLs for efficient, high-stability, saturated LEDs.
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Affiliation(s)
- Umberto Giovanella
- Istituto per lo Studio delle Macromolecole , Consiglio Nazionale delle Ricerche (ISMac-CNR) , Via Bassini 15 , 20133 Milano , Italy
| | - Mariacecilia Pasini
- Istituto per lo Studio delle Macromolecole , Consiglio Nazionale delle Ricerche (ISMac-CNR) , Via Bassini 15 , 20133 Milano , Italy
| | - Monica Lorenzon
- Dipartimento di Scienza dei Materiali , Università degli Studi di Milano-Bicocca , via Cozzi 55 , I-20125 Milano , Italy
| | - Francesco Galeotti
- Istituto per lo Studio delle Macromolecole , Consiglio Nazionale delle Ricerche (ISMac-CNR) , Via Bassini 15 , 20133 Milano , Italy
| | - Claudio Lucchi
- Dipartimento di Scienza dei Materiali , Università degli Studi di Milano-Bicocca , via Cozzi 55 , I-20125 Milano , Italy
| | - Francesco Meinardi
- Dipartimento di Scienza dei Materiali , Università degli Studi di Milano-Bicocca , via Cozzi 55 , I-20125 Milano , Italy
| | - Silvia Luzzati
- Istituto per lo Studio delle Macromolecole , Consiglio Nazionale delle Ricerche (ISMac-CNR) , Via Bassini 15 , 20133 Milano , Italy
| | - Benoit Dubertret
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-ParisTech , PSL Research University, Sorbonne Université UPMC Université Paris 06, CNRS , 10 rue Vauquelin , 75005 Paris , France
| | - Sergio Brovelli
- Dipartimento di Scienza dei Materiali , Università degli Studi di Milano-Bicocca , via Cozzi 55 , I-20125 Milano , Italy
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Panfil YE, Oded M, Banin U. Colloidal Quantum Nanostructures: Emerging Materials for Display Applications. Angew Chem Int Ed Engl 2018; 57:4274-4295. [PMID: 28975692 PMCID: PMC6001641 DOI: 10.1002/anie.201708510] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Indexed: 11/11/2022]
Abstract
Colloidal semiconductor nanocrystals (SCNCs) or, more broadly, colloidal quantum nanostructures constitute outstanding model systems for investigating size and dimensionality effects. Their nanoscale dimensions lead to quantum confinement effects that enable tuning of their optical and electronic properties. Thus, emission color control with narrow photoluminescence spectra, wide absorbance spectra, and outstanding photostability, combined with their chemical processability through control of their surface chemistry leads to the emergence of SCNCs as outstanding materials for present and next-generation displays. In this Review, we present the fundamental chemical and physical properties of SCNCs, followed by a description of the advantages of different colloidal quantum nanostructures for display applications. The open challenges with respect to their optical activity are addressed. Both photoluminescent and electroluminescent display scenarios utilizing SCNCs are described.
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Affiliation(s)
- Yossef E. Panfil
- Institute of Chemistry and the Center for Nanoscience and NanotechnologyThe Hebrew University of JerusalemJerusalem9190401Israel
| | - Meirav Oded
- Institute of Chemistry and the Center for Nanoscience and NanotechnologyThe Hebrew University of JerusalemJerusalem9190401Israel
| | - Uri Banin
- Institute of Chemistry and the Center for Nanoscience and NanotechnologyThe Hebrew University of JerusalemJerusalem9190401Israel
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Panfil YE, Oded M, Banin U. Kolloidale Quantennanostrukturen: neue Materialien für Displayanwendungen. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201708510] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yossef E. Panfil
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
| | - Meirav Oded
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
| | - Uri Banin
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology; The Hebrew University of Jerusalem; Jerusalem 9190401 Israel
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Rastogi P, Palazon F, Prato M, Di Stasio F, Krahne R. Enhancing the Performance of CdSe/CdS Dot-in-Rod Light-Emitting Diodes via Surface Ligand Modification. ACS APPLIED MATERIALS & INTERFACES 2018; 10:5665-5672. [PMID: 29355299 DOI: 10.1021/acsami.7b18780] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The surface ligands on colloidal nanocrystals (NCs) play an important role in the performance of NC-based optoelectronic devices such as photovoltaic cells, photodetectors, and light-emitting diodes (LEDs). On one hand, the NC emission depends critically on the passivation of the surface to minimize trap states that can provide nonradiative recombination channels. On the other hand, the electrical properties of NC films are dominated by the ligands that constitute the barriers for charge transport from one NC to its neighbor. Therefore, surface modifications via ligand exchange have been employed to improve the conductance of NC films. However, in LEDs, such surface modifications are more critical because of their possible detrimental effects on the emission properties. In this work, we study the role of surface ligand modifications on the optical and electrical properties of CdSe/CdS dot-in-rods (DiRs) in films and investigate their performance in all-solution-processed LEDs. The DiR films maintain high photoluminescence quantum yield, around 40-50%, and their electroluminescence in the LED preserves the excellent color purity of the photoluminescence. In the LEDs, the ligand exchange boosted the luminance, reaching a fourfold increase from 2200 cd/m2 for native surfactants to 8500 cd/m2 for the exchanged aminoethanethiol (AET) ligands. Moreover, the efficiency roll-off, operational stability, and shelf life are significantly improved, and the external quantum efficiency is modestly increased from 5.1 to 5.4%. We relate these improvements to the increased conductivity of the emissive layer and to the better charge balance of the electrically injected carriers. In this respect, we performed ultraviolet photoelectron spectroscopy (UPS) to obtain a deeper insight into the band alignment of the LED structure. The UPS data confirm similar flat-band offsets of the emitting layer to the electron- and hole-transport layers in the case of AET ligands, which translates to more symmetric barriers for charge injection of electrons and holes. Furthermore, the change in solubility of the NCs induced by the ligand exchange allows for a layer-by-layer deposition process of the DiR films, which yields excellent homogeneity and good thickness control and enables the fabrication of all the LED layers (except for cathode and anode) by spin-coating.
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Affiliation(s)
- Prachi Rastogi
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova , Via Dodecaneso 31, 16146 Genova, Italy
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Kim D, Lee YK, Lee D, Kim WD, Bae WK, Lee DC. Colloidal Dual-Diameter and Core-Position-Controlled Core/Shell Cadmium Chalcogenide Nanorods. ACS NANO 2017; 11:12461-12472. [PMID: 29131591 DOI: 10.1021/acsnano.7b06542] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
To capitalize on shape- and structure-dependent properties of semiconductor nanorods (NRs), high-precision control and exquisite design of their growth are desired. Cadmium chalcogenide (CdE; E = S or Se) NRs are the most studied class of such, whose growth exhibits axial anisotropy, i.e., different growth rates along the opposite directions of {0001} planes. However, the mechanism behind asymmetric axial growth of NRs remains unclear because of the difficulty in instant analysis of growth surfaces. Here, we design colloidal dual-diameter semiconductor NRs (DDNRs) under the quantum confinement regime, which have two sections along the long axis with different diameters. The segmentation of the DDNRs allows rigorous assessment of the kinetics of NR growth at a molecular level. The reactivity of a terminal facet passivated by an organic ligand is governed by monomer diffusivity through the surface ligand monolayer. Therefore, the growth rate in two polar directions can be finely tuned by controlling the strength of ligand-ligand attraction at end surfaces. Building on these findings, we report the synthesis of single-diameter CdSe/CdS core/shell NRs with CdSe cores of controllable position, which reveals a strong structure-optical polarization relationship. The understanding of the NR growth mechanism with controllable anisotropy will serve as a cornerstone for the exquisite design of more complex anisotropic nanostructures.
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Affiliation(s)
- Dahin Kim
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea
| | - Young Kuk Lee
- Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT) , Daejeon 34114, Korea
| | - Dongkyu Lee
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea
| | - Whi Dong Kim
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea
| | - Wan Ki Bae
- Photoelectronic Hybrids Research Center, Korea Institute of Science and Technology (KIST) , Seoul 02792, Korea
| | - Doh C Lee
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea
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Lee S, Flanagan JC, Lee B, Hwang T, Kim J, Gil B, Shim M, Park B. Route to Improving Photovoltaics Based on CdSe/CdSe xTe 1-x Type-II Heterojunction Nanorods: The Effect of Morphology and Cosensitization on Carrier Recombination and Transport. ACS APPLIED MATERIALS & INTERFACES 2017; 9:31931-31939. [PMID: 28850210 DOI: 10.1021/acsami.7b09745] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
One-dimensionally elongated nanoparticles with type-II staggered band offset are of potential use as light-harvesting materials for photovoltaics, but only a limited attention has been given to elucidate the factors governing the cell performance obtainable from such materials. Herein, we describe a combined strategy to enhance charge collection from CdSe/CdSexTe1-x type-II heterojunction nanorods (HNRs) utilized as light harvesters for sensitized solar cells. By integrating morphology- and composition-tuned type-II HNRs into solar cells, factors that yield interfaces favorable both for the electron injection into TiO2 and hole transfer to electrolyte are examined. Furthermore, it is shown that a more efficient photovoltaic system results from cosensitization with CdS quantum dots (QDs) predeposited on a TiO2 scaffold, which improves charge collection from HNRs. Electrochemical impedance spectroscopy (EIS) analysis suggests that such a synergistically enhanced system benefits from the decreased recombination within HNRs and facilitated charge transport through the cosensitized TiO2 electrode, even with the activation of a recombination path presumably related to the photogenerated holes in CdS QDs.
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Affiliation(s)
- Sangheon Lee
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University , Seoul 08226, Korea
| | - Joseph C Flanagan
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Byungho Lee
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University , Seoul 08226, Korea
| | - Taehyun Hwang
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University , Seoul 08226, Korea
| | - Jaewook Kim
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University , Seoul 08226, Korea
| | - Bumjin Gil
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University , Seoul 08226, Korea
| | - Moonsub Shim
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Byungwoo Park
- WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University , Seoul 08226, Korea
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Ji B, Panfil YE, Banin U. Heavy-Metal-Free Fluorescent ZnTe/ZnSe Nanodumbbells. ACS NANO 2017; 11:7312-7320. [PMID: 28654241 DOI: 10.1021/acsnano.7b03407] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
For visible range emitting particles, which are relevant for display and additional applications, Cd-chalcogenide nanocrystals have reached the highest degree of control and performance. Considering potential toxicity and regulatory limitations, there is a challenge to successfully develop Cd-free emitting nanocrystals and, in particular, heterostructures with desirable properties. Herein, we report a colloidal synthesis of fluorescent heavy-metal-free Zn-chalcogenide semiconductor nanodumbbells (NDBs), in which ZnSe tips were selectively grown on the apexes of ZnTe rods, as evidenced by a variety of methods. The fluorescence of the NDBs can be tuned between ∼500 and 585 nm by changing the ZnSe tip size. The emission quantum yield can be greatly increased through chloride surface treatment and reaches more than 30%. Simulations within an effective-mass-based model show that the hole wave function is spread over the ZnTe nanorods, while the electron wave function is localized on the ZnSe tips. Quantitative agreement for the red-shifted emission wavelength is obtained between the simulations and the experiments. Additionally, the changes in radiative lifetimes correlate well with the calculated decrease in electron-hole overlap upon growth of larger ZnSe tips. The heavy-metal-free ZnTe/ZnSe NDBs may be relevant for optoelectronic applications such as displays or light-emitting diodes.
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Affiliation(s)
- Botao Ji
- The Institute of Chemistry and Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
| | - Yossef E Panfil
- The Institute of Chemistry and Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
| | - Uri Banin
- The Institute of Chemistry and Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
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43
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Liang F, Liu Y, Hu Y, Shi YL, Liu YQ, Wang ZK, Wang XD, Sun BQ, Liao LS. Polymer as an Additive in the Emitting Layer for High-Performance Quantum Dot Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2017; 9:20239-20246. [PMID: 28541652 DOI: 10.1021/acsami.7b05629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A facile but effective method is proposed to improve the performance of quantum dot light-emitting diodes (QLEDs) by incorporating a polymer, poly(9-vinlycarbazole) (PVK), as an additive into the CdSe/CdS/ZnS quantum dot (QD) emitting layer (EML). It is found that the charge balance of the device with the PVK-added EML was greatly improved. In addition, the film morphology of the hole-transporting layer (HTL) which is adjacent to the EML, is substantially improved. The surface roughness of the HTL is reduced from 5.87 to 1.38 nm, which promises a good contact between the HTL and the EML, resulting in low leakage current. With the improved charge balance and morphology, a maximum external quantum efficiency (EQE) of 16.8% corresponding to the current efficiency of 19.0 cd/A is achievable in the red QLEDs. The EQE is 1.6 times as high as that (10.5%) of the reference QLED, comprising a pure QD EML. This work demonstrates that incorporating some polymer molecules into the QD EML as additives could be a facile route toward high-performance QLEDs.
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Affiliation(s)
- Feng Liang
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Yuan Liu
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Yun Hu
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Ying-Li Shi
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Yu-Qiang Liu
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Zhao-Kui Wang
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Xue-Dong Wang
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Bao-Quan Sun
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Liang-Sheng Liao
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
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Cho SY, Oh N, Nam S, Jiang Y, Shim M. Enhanced device lifetime of double-heterojunction nanorod light-emitting diodes. NANOSCALE 2017; 9:6103-6110. [PMID: 28447691 DOI: 10.1039/c7nr01404j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Colloidal quantum dots (QDs) are emerging as solution-processable, high-performance materials for light-emitting diodes (LEDs). Understanding the failure mechanism(s) is of both fundamental and practical importance, yet little is known of how QD-LEDs fail. Here, we have carried out accelerated device lifetime measurements on double heterojunction nanorod- (DHNR) and QD-LEDs. A common dependence of device lifetime on the initial driving voltage is observed over more than two orders of magnitude range in the initial luminance. This behavior is independent of whether the emitting materials are DHNRs or QDs prepared under different conditions. Reducing the hole injection barrier by doping HTL allows lower voltage operation, leading to longer device lifetimes. DHNRs with a band structure that further lowers the hole injection barrier require even lower driving voltages and therefore lead to longer device lifetimes than core/shell QDs. At 1000 cd m-2, the DHNR-LED exhibits no significant degradation even after more than 200 h of continuous operation. QD-LEDs, on the other hand, are completely degraded in less than ∼100 h under the same initial luminance conditions. Hole accumulation/trapping leading to HTL degradation, which in turn deteriorates electroluminescence but not the photoluminescence, is suggested to be the main cause of degradation of both DHNR- and QD-LEDs.
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Affiliation(s)
- Seong-Yong Cho
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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45
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Zou Y, Liu Y, Ban M, Huang Q, Sun T, Zhang Q, Song T, Sun B. Crosslinked conjugated polymers as hole transport layers in high-performance quantum dot light-emitting diodes. NANOSCALE HORIZONS 2017; 2:156-162. [PMID: 32260659 DOI: 10.1039/c6nh00217j] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Film morphologies of functional layers in all-solution-processed quantum dot light-emitting diodes (QLEDs) play a crucial role in device performance. Solvents for adjacent layers should be strictly orthogonal to prevent the preceding layer being redissolved by the processing solvent of the next layer. Herein, we use a photochemical crosslinking method to obtain solvent-resistant hole transport layers (HTLs) with photoinitiator bifunctional bis-benzophenone (BP-BP). With this method, ultra-smooth quantum dot (QD) layers can be fabricated using toluene as solvent, which is known to be a nonorthogonal solvent in common non-crosslinked HTLs. A green QLED device based on crosslinked HTLs exhibits a high external quantum efficiency of 8.93%, which is 1.9-fold higher than that of the non-crosslinked device. The improved device performance is ascribed to the well preserved film morphology of crosslinked HTLs and the prevention of QDs intermixing with HTLs during the QD deposition in toluene. This crosslinking strategy avoids high-temperature annealing, allowing the fabrication of flexible devices on plastic substrates. Moreover, it broadens the range of applicable solvents for solution-processed multilayer optoelectronic devices because non-orthogonal solvents can be used after crosslinking preceding layers.
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Affiliation(s)
- Yatao Zou
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, 199 Ren'ai Road, Suzhou 215123, People's Republic of China.
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Pietryga JM, Park YS, Lim J, Fidler AF, Bae WK, Brovelli S, Klimov VI. Spectroscopic and Device Aspects of Nanocrystal Quantum Dots. Chem Rev 2017; 116:10513-622. [PMID: 27677521 DOI: 10.1021/acs.chemrev.6b00169] [Citation(s) in RCA: 395] [Impact Index Per Article: 56.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The field of nanocrystal quantum dots (QDs) is already more than 30 years old, and yet continuing interest in these structures is driven by both the fascinating physics emerging from strong quantum confinement of electronic excitations, as well as a large number of prospective applications that could benefit from the tunable properties and amenability toward solution-based processing of these materials. The focus of this review is on recent advances in nanocrystal research related to applications of QD materials in lasing, light-emitting diodes (LEDs), and solar energy conversion. A specific underlying theme is innovative concepts for tuning the properties of QDs beyond what is possible via traditional size manipulation, particularly through heterostructuring. Examples of such advanced control of nanocrystal functionalities include the following: interface engineering for suppressing Auger recombination in the context of QD LEDs and lasers; Stokes-shift engineering for applications in large-area luminescent solar concentrators; and control of intraband relaxation for enhanced carrier multiplication in advanced QD photovoltaics. We examine the considerable recent progress on these multiple fronts of nanocrystal research, which has resulted in the first commercialized QD technologies. These successes explain the continuing appeal of this field to a broad community of scientists and engineers, which in turn ensures even more exciting results to come from future exploration of this fascinating class of materials.
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Affiliation(s)
- Jeffrey M Pietryga
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Young-Shin Park
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.,Center for High Technology Materials, University of New Mexico , Albuquerque, New Mexico 87131, United States
| | - Jaehoon Lim
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Andrew F Fidler
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Wan Ki Bae
- Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology , Seoul 02792, Korea
| | - Sergio Brovelli
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , I-20125 Milano, Italy
| | - Victor I Klimov
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
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Dai X, Deng Y, Peng X, Jin Y. Quantum-Dot Light-Emitting Diodes for Large-Area Displays: Towards the Dawn of Commercialization. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1607022. [PMID: 28256780 DOI: 10.1002/adma.201607022] [Citation(s) in RCA: 252] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/02/2017] [Indexed: 05/21/2023]
Abstract
Quantum dots are a unique class of emitters with size-tunable emission wavelengths, saturated emission colors, near-unity luminance efficiency, inherent photo- and thermal- stability and excellent solution processability. Quantum dots have been used as down-converters for back-lighting in liquid-crystal displays to improve color gamut, leading to the booming of quantum-dot televisions in consumer market. In the past few years, efficiency and lifetime of electroluminescence devices based on quantum dots achieved tremendous progress. These encouraging facts foreshadow the commercialization of quantum-dot light-emitting diodes (QLEDs), which promises an unprecedented generation of cost-effective, large-area, energy-saving, wide-color-gamut, ultra-thin and flexible displays. Here we provide a Progress Report, covering interdisciplinary aspects including material chemistry of quantum dots and charge-transporting layers, optimization and mechanism studies of prototype devices and processing techniques to produce large-area and high-resolution red-green-blue pixel arrays. We also identify a few key challenges facing the development of active-matrix QLED displays.
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Affiliation(s)
- Xingliang Dai
- Center for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Yunzhou Deng
- Center for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Xiaogang Peng
- Center for Chemistry of High-Performance & Novel Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Yizheng Jin
- Center for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310027, People's Republic of China
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48
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Oh N, Kim BH, Cho SY, Nam S, Rogers SP, Jiang Y, Flanagan JC, Zhai Y, Kim JH, Lee J, Yu Y, Cho YK, Hur G, Zhang J, Trefonas P, Rogers JA, Shim M. Double-heterojunction nanorod light-responsive LEDs for display applications. Science 2017; 355:616-619. [DOI: 10.1126/science.aal2038] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/12/2017] [Indexed: 01/07/2023]
Affiliation(s)
- Nuri Oh
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Bong Hoon Kim
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Seong-Yong Cho
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Sooji Nam
- Information Control Device Research Section, Electronics and Telecommunications Research Institute, Daejeon, 305-700, Republic of Korea
| | - Steven P Rogers
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yiran Jiang
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Joseph C Flanagan
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - You Zhai
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jae-Hwan Kim
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jungyup Lee
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yongjoon Yu
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Youn Kyoung Cho
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Gyum Hur
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jieqian Zhang
- Dow Electronic Materials, 455 Forest Street, Marlborough, MA 01752, USA
| | - Peter Trefonas
- Dow Electronic Materials, 455 Forest Street, Marlborough, MA 01752, USA
| | - John A Rogers
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Moonsub Shim
- Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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49
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Keum H, Jiang Y, Park JK, Flanagan JC, Shim M, Kim S. Solvent-Free Patterning of Colloidal Quantum Dot Films Utilizing Shape Memory Polymers. MICROMACHINES 2017. [PMCID: PMC6189828 DOI: 10.3390/mi8010018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Colloidal quantum dots (QDs) with properties that can be tuned by size, shape, and composition are promising for the next generation of photonic and electronic devices. However, utilization of these materials in such devices is hindered by the limited compatibility of established semiconductor processing techniques. In this context, patterning of QD films formed from colloidal solutions is a critical challenge and alternative methods are currently being developed for the broader adoption of colloidal QDs in functional devices. Here, we present a solvent-free approach to patterning QD films by utilizing a shape memory polymer (SMP). The high pull-off force of the SMP below glass transition temperature (Tg) in conjunction with the conformal contact at elevated temperatures (above Tg) enables large-area, rate-independent, fine patterning while preserving desired properties of QDs.
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Affiliation(s)
- Hohyun Keum
- Department of Mechanical Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL 61801, USA; (H.K.); (J.K.P.)
| | - Yiran Jiang
- Department of Material Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL 61801, USA; (Y.J.); (J.C.F.); (M.S.)
| | - Jun Kyu Park
- Department of Mechanical Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL 61801, USA; (H.K.); (J.K.P.)
| | - Joseph C. Flanagan
- Department of Material Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL 61801, USA; (Y.J.); (J.C.F.); (M.S.)
| | - Moonsub Shim
- Department of Material Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL 61801, USA; (Y.J.); (J.C.F.); (M.S.)
| | - Seok Kim
- Department of Mechanical Science and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL 61801, USA; (H.K.); (J.K.P.)
- Correspondence: ; Tel.: +1-217-265-5656
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Wang C, Peng D, Zhao J, Bao R, Li T, Tian L, Dong L, Shen C, Pan C. CdS@SiO 2 Core-Shell Electroluminescent Nanorod Arrays Based on a Metal-Insulator-Semiconductor Structure. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:5734-5740. [PMID: 27572124 DOI: 10.1002/smll.201601548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 07/27/2016] [Indexed: 06/06/2023]
Abstract
Enormous advancement has been achieved in the field of one-dimensional (1D) semiconductor light-emitting devices (LEDs), however, LEDs based on 1D CdS nanostructures have been rarely reported. The fabrication of CdS@SiO2 core-shell nanorod array LEDs based on a Au-SiO2 -CdS metal-insulator-semiconductor (MIS) structure is presented. The MIS LEDs exhibit strong yellow emission with a low threshold voltage of 2.7 V. Electroluminescence with a broad emission ranging from 450 nm to 800 nm and a shoulder peak at 700 nm is observed, which is related to the defects and surface states of the CdS nanorods. The influence of the SiO2 shell thickness on the electroluminescence intensity is systematically investigated. The devices have a high light-emitting spatial resolution of 1.5 μm and maintain an excellent emission property even after shelving at room temperature for at least three months. Moreover, the fabrication process is simple and cost effective and the MIS device could be fabricated on a flexible substrate, which holds great potential for application as a flexible light source. This prototype is expected to open up a new route towards the development of large-scale light-emitting devices with excellent attributes, such as high resolution, low cost, and good stability.
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Affiliation(s)
- Chunfeng Wang
- Engineering Research Center for Advanced Polymer Processing Technology, School of Materials Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Dengfeng Peng
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Jing Zhao
- Engineering Research Center for Advanced Polymer Processing Technology, School of Materials Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Rongrong Bao
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Tianfeng Li
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Li Tian
- Engineering Research Center for Advanced Polymer Processing Technology, School of Materials Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China
| | - Lin Dong
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China.
- School of Physical Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China.
| | - Changyu Shen
- Engineering Research Center for Advanced Polymer Processing Technology, School of Materials Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China.
| | - Caofeng Pan
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China.
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