1
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Li Q, Wu K, Zhu H, Yang Y, He S, Lian T. Charge Transfer from Quantum-Confined 0D, 1D, and 2D Nanocrystals. Chem Rev 2024; 124:5695-5763. [PMID: 38629390 PMCID: PMC11082908 DOI: 10.1021/acs.chemrev.3c00742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/29/2024] [Accepted: 04/02/2024] [Indexed: 05/09/2024]
Abstract
The properties of colloidal quantum-confined semiconductor nanocrystals (NCs), including zero-dimensional (0D) quantum dots, 1D nanorods, 2D nanoplatelets, and their heterostructures, can be tuned through their size, dimensionality, and material composition. In their photovoltaic and photocatalytic applications, a key step is to generate spatially separated and long-lived electrons and holes by interfacial charge transfer. These charge transfer properties have been extensively studied recently, which is the subject of this Review. The Review starts with a summary of the electronic structure and optical properties of 0D-2D nanocrystals, followed by the advances in wave function engineering, a novel way to control the spatial distribution of electrons and holes, through their size, dimension, and composition. It discusses the dependence of NC charge transfer on various parameters and the development of the Auger-assisted charge transfer model. Recent advances in understanding multiple exciton generation, decay, and dissociation are also discussed, with an emphasis on multiple carrier transfer. Finally, the applications of nanocrystal-based systems for photocatalysis are reviewed, focusing on the photodriven charge separation and recombination processes that dictate the function and performance of these materials. The Review ends with a summary and outlook of key remaining challenges and promising future directions in the field.
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Affiliation(s)
- Qiuyang Li
- Department
of Physics, University of Michigan, 450 Church St, Ann Arbor, Michigan 48109, United States
| | - Kaifeng Wu
- State
Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation
Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Haiming Zhu
- Department
of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Ye Yang
- The
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM
(Collaborative Innovation Center of Chemistry for Energy Materials),
College of Chemistry & Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Sheng He
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Tianquan Lian
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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2
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Raulerson EK, Cadena DM, Jabed MA, Wight CD, Lee I, Wagner HR, Brewster JT, Iverson BL, Kilina S, Roberts ST. Using Spectator Ligands to Enhance Nanocrystal-to-Molecule Electron Transfer. J Phys Chem Lett 2022; 13:1416-1423. [PMID: 35119280 DOI: 10.1021/acs.jpclett.1c03825] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Semiconductor nanocrystals (NCs) have emerged as promising photocatalysts. However, NCs are often functionalized with complex ligand shells that contain not only charge acceptors but also other "spectator ligands" that control NC solubility and affinity for target reactants. Here, we show that spectator ligands are not passive observers of photoinduced charge transfer but rather play an active role in this process. We find the rate of electron transfer from quantum-confined PbS NCs to perylenediimide acceptors can be varied by over a factor of 4 simply by coordinating cinnamate ligands with distinct dipole moments to NC surfaces. Theoretical calculations indicate this rate variation stems from both ligand-induced changes in the free energy for charge transfer and electrostatic interactions that alter perylenediimide electron acceptor orientation on NC surfaces. Our work shows NC-to-molecule charge transfer can be fine-tuned through ligand shell design, giving researchers an additional handle for enhancing NC photocatalysis.
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Affiliation(s)
- Emily K Raulerson
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Danielle M Cadena
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Mohammed A Jabed
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Christopher D Wight
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Inki Lee
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Holden R Wagner
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - James T Brewster
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Brent L Iverson
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Svetlana Kilina
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Sean T Roberts
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
- Center for Dynamics and Control of Materials, The University of Texas at Austin, Austin, Texas 78712, United States
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3
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Jayachandran P, Angamuthu A, Gopalan P. Redox potentials of puckered 1,4-benzoquinone. J CHEM SCI 2022. [DOI: 10.1007/s12039-021-02005-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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4
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Effects of surface hydration on the electron injection rate from graphene to anatase and rutile TiO2 surfaces. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.110463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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5
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Shang Q, Kaledin AL, Li Q, Lian T. Size dependent charge separation and recombination in CsPbI 3 perovskite quantum dots. J Chem Phys 2019; 151:074705. [PMID: 31438693 DOI: 10.1063/1.5109894] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
CsPbI3 perovskite quantum dots (QDs) have shown great potential in light-harvesting and light-emitting applications, which often involve the transfer of charge carriers in and out of these materials. Here, we studied size-dependent charge separation (CS) and charge recombination (CR) between CsPbI3 QDs and rhodamine B (RhB) molecules, using transient absorption spectroscopy. When the average size decreases from 11.8 nm to 6.5 nm, the average intrinsic CS time constant decreases from 872 ± 52 ps to 40.6 ± 4.3 ps and the corresponding charge recombination time constant decreases from 3829 ± 51 ns to 1384 ± 54 ns. The observed trend of size-dependent CS and CR rates can be well explained by Marcus theory using the theoretically calculated CS and CR driving forces (ΔGCS and ΔGCR), molecular reorganization energy (λRhB), and electronic coupling strength between QD and RhB (HCS and HCR). Unlike the extensively studied more strongly quantum confined Cd chalcogenide QDs, the CsPbI3 QDs are in a weak quantum confinement regime in which size-dependent coupling strength plays a dominant role in the size-dependent charge transfer properties.
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Affiliation(s)
- Qiongyi Shang
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Alexey L Kaledin
- Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Qiuyang Li
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Tianquan Lian
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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6
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Zhao H, Li Y, Diao L, Sun C, Shi Y. Reevaluating the effects of reorganization energy on electron transfer rate for quantum dot-molecular acceptor complexes in different solvents. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 218:237-242. [PMID: 31003048 DOI: 10.1016/j.saa.2019.04.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/28/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
The electron transfer (ET) rate in quantum dot (QD)-molecular acceptor systems is dependent upon system reorganization energy (RE, λ), which comprises contributions from solvent (λ0) and reactants (λi). However, to date, the effect of λi on ET rate has been largely ignored. Herein, the ET from CdSe/ZnS QDs to 1-chloroanthraquinone (1-CAQ) in different solvents was investigated using ultrafast transient absorption spectroscopy as a means to evaluate the effect of λi on ET rate. The results revealed that ET rate is strongly solvent dependent. Amazingly, the ET rate in carbon disulfide is 300-times higher than that in n-dodecane. Theoretical calculations indicated that the λi contribution from 1-CAQ alone accounts for a large proportion of system RE and varies greatly in different solvents. Furthermore, the ET rate increases first and, then, decreases with the λ value in different solvents. This trend was interpreted consistently in terms of Marcus theory by adding λi to λ for different solvents. Thus, our present work demonstrates that the RE of the acceptor molecule has a non-negligible effect on ET rate, providing new insight into the mechanisms of ET process and for the development of QD-based devices.
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Affiliation(s)
- Huifang Zhao
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - You Li
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Lihe Diao
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Chaofan Sun
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
| | - Ying Shi
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
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7
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Zhao H, Yin H, Liu X, Li H, Shi Y, Liu C, Jin M, Gao J, Luo Y, Ding D. Pressure-Induced Tunable Electron Transfer and Auger Recombination Rates in CdSe/ZnS Quantum Dot-Anthraquinone Complexes. J Phys Chem Lett 2019; 10:3064-3070. [PMID: 31120761 DOI: 10.1021/acs.jpclett.9b01048] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Electron transfer (ET) and Auger recombination (AR) processes in quantum dots (QDs) are key mechanisms for the advance of QD-based devices. However, it still remains a challenge to promote ET and suppress AR simultaneously. Here, we use in situ high-pressure ultrafast transient absorption spectroscopy to explore the impact of pressure on the ET between CdSe/ZnS and anthraquinone (AQ) and AR dissolved in cyclohexane. Remarkably, under compression, ET lifetimes are shorten, while suppression of AR lifetimes is present. The promotion of ET is attributed to the shortened distance between CdSe/ZnS and AQ induced by pressure. We rationalize that for the AR suppression, pressure may enhance the formation of an alloy layer at the core/shell interface. These findings indicate that compression is an effective approach to promote ET and suppress AR simultaneously. This study highlights a brand-new approach for modulating ET and AR and provides new routes toward QD-based applications.
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Affiliation(s)
- Huifang Zhao
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Hang Yin
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Xiaochun Liu
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Hui Li
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Ying Shi
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Cailong Liu
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Mingxing Jin
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
| | - Jianbo Gao
- Ultrafast Photophysics of Quantum Devices Laboratory, Department of Physics and Astronomy , Clemson University , Clemson , South Carolina 29634 , United States
| | - Yi Luo
- Hefei National Laboratory for Physical Sciences at the Microscale , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Dajun Ding
- Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China
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8
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Tunable electron transfer rate in a CdSe/ZnS-based complex with different anthraquinone chloride substitutes. Sci Rep 2019; 9:7756. [PMID: 31123306 PMCID: PMC6533304 DOI: 10.1038/s41598-019-44325-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 05/13/2019] [Indexed: 11/08/2022] Open
Abstract
We use femtosecond transient absorption spectroscopy to study ultrafast electron transfer (ET) dynamics in a model donor and acceptor system using CdSe/ZnS core/shell structure quantum dots (QDs) as donors and anthraquinone (AQ) molecules as acceptors. The ET rate can be enhanced by decreasing the number of chlorine substituents in the AQ molecules because that increases the driving force, which is the energy level offset between the conduction band energy of CdSe/ZnS and the lowest upper molecular orbital potential of AQ derivatives, as confirmed by cyclic voltammetry measurements. However, the electronic coupling between the QDs and AQ derivatives, and the sum of reorganization energy of AQ molecules and solvent calculated by density functional theory are not the main reasons for the change in ET rate in three systems. Our findings provide new insights into selecting an acceptor molecule and will be useful in tuning ET processes for advanced QD-based applications.
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9
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Kaledin AL, Hill CL, Lian T, Musaev DG. Modulating electronic coupling at the quantum dot/molecule interface by wavefunction engineering. J Chem Phys 2019; 150:124704. [DOI: 10.1063/1.5083056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Alexey L. Kaledin
- Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Craig L. Hill
- Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Tianquan Lian
- Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Djamaladdin G. Musaev
- Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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10
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Exhibition of Förster resonance energy transfer from CdSe/ZnS quantum dots to zinc porphyrazine studied in solution. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.11.141] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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11
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Kaledin AL, Hill CL, Lian T, Musaev DG. A bulk adjusted linear combination of atomic orbitals (BA-LCAO) approach for nanoparticles. J Comput Chem 2018; 40:212-221. [PMID: 30284306 DOI: 10.1002/jcc.25373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 11/11/2022]
Abstract
We describe a bulk adjusted linear combination of atomic orbitals (BA-LCAO) approach for nanoparticles. In this method, we apply a many-body scaling function (in similar manner as in the environment-modified total energy based tight-binding method) to the DFT-derived diatomic AO interaction potentials (like in the conventional orbital-based density-functional tight binding approach) strictly according to atomic valences acquired naturally in a bulk structure. This modification, (a) facilitates all atom orbital-based electronic structure calculations of charge carrier dynamics in nanoscale structures with a molecular acceptor, and (b) allows to closely match high-level density functional calculation data (previously adjusted to the available experimental findings) for bulk structures. To advance practical application of the BA-LCAO approach we parameterize the Hamiltonian of wurtzite CdSe by fitting its band structure to a high-level DFT reference, corrected for experimentally measured band edges. Here, unlike in conventional DFTB approach, we: (1) use hydrogen-like AOs for the basis as exact atomic eigenfunctions, while orbital energies of which are taken from experimentally measured ionization potentials, and (2) parameterize the many-body scaling functions rather than the atomic wavefunctions. Development of this approach and parameters is guided by our goals to devise a method capable of simultaneously treating the problems of (i) interfacial electron/hole transfer between finite, variable size nanoparticles and electron scavenging molecules, and (ii) high-energy electronic transitions (Auger transitions) that mediate multi-exciton decay in quantum dots. Electronic structure results are described for CdSe quantum dots of various sizes. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Alexey L Kaledin
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, 30322, Georgia
| | - Craig L Hill
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, 30322, Georgia
| | - Tianquan Lian
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, 30322, Georgia
| | - Djamaladdin G Musaev
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, 30322, Georgia
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12
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Tkachenko NV. Photoinduced Charge Separation in Semiconductor-Quantum-Dot/Organic-Molecule Hybrids. CHEMPHOTOCHEM 2017. [DOI: 10.1002/cptc.201700161] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Nikolai V. Tkachenko
- Laboratory of Chemistry and Bioengineering; Tampere University of Technology; P.O.Box 541 33101 Tampere Finland
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13
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Shi YL, Liang F, Hu Y, Zhuo MP, Wang XD, Liao LS. High performance blue quantum dot light-emitting diodes employing polyethylenimine ethoxylated as the interfacial modifier. NANOSCALE 2017; 9:14792-14797. [PMID: 28953275 DOI: 10.1039/c7nr04542e] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Efficient electron-injection into the emitting layer (EML) plays a pivotal role in the fabrication of high performance blue quantum dot light-emitting diodes (QLEDs). Herein, we reduce the electron-transporting barrier at the ITO/ETL (electron-transporting layer) interface from 0.7 eV to 0.4 eV by spin-coating a polyethylenimine ethoxylated (PEIE) film (8 nm) on the ITO substrate. Meanwhile, the electron-injection barrier was reduced from 0.5 to 0.1 eV at the ETL/QD interface by employing the incorporation of PEIE (0.1 wt%) into a ZnO layer. These above two interfacial modifications jointly decrease the electron barrier and make the electron transportation easier. As a result, the optimized QLEDs with the 460 nm emission peak exhibit a maximum external quantum efficiency (EQE) of 7.85%, which is enhanced by 1.4 fold compared with the reference device (5.68%). It is demonstrated that the facile interfacial modification by the organic polymer PEIE contributes to the fabrication of high-efficiency blue QLEDs.
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Affiliation(s)
- 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.
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14
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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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15
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Experimental and Theoretical Reduction Potentials of Some Biologically Active ortho-Carbonyl para-Quinones. Molecules 2017; 22:molecules22040577. [PMID: 28375183 PMCID: PMC6154728 DOI: 10.3390/molecules22040577] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 03/14/2017] [Accepted: 03/29/2017] [Indexed: 12/22/2022] Open
Abstract
The rational design of quinones with specific redox properties is an issue of great interest because of their applications in pharmaceutical and material sciences. In this work, the electrochemical behavior of a series of four p-quinones was studied experimentally and theoretically. The first and second one-electron reduction potentials of the quinones were determined using cyclic voltammetry and correlated with those calculated by density functional theory (DFT) using three different functionals, BHandHLYP, M06-2x and PBE0. The differences among the experimental reduction potentials were explained in terms of structural effects on the stabilities of the formed species. DFT calculations accurately reproduced the first one-electron experimental reduction potentials with R2 higher than 0.94. The BHandHLYP functional presented the best fit to the experimental values (R2 = 0.957), followed by M06-2x (R2 = 0.947) and PBE0 (R2 = 0.942).
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16
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Arvani M, Virkki K, Abou-Chahine F, Efimov A, Schramm A, Tkachenko NV, Lupo D. Photoinduced hole transfer in QD-phthalocyanine hybrids. Phys Chem Chem Phys 2016; 18:27414-27421. [PMID: 27722635 DOI: 10.1039/c6cp04374g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A series of CdSe quantum dot (QD)-phthalocyanine (Pc) hybrids were synthesized and their photophysics was studied using steady state and time-resolved spectroscopic methods. Emission of QDs was progressively quenched upon increasing the concentration of Pc in the hybrids. A detailed transient absorption study of the hybrids revealed that the mechanism of quenching is charge separation, resulting in the formation of hybrids with negatively charged QDs and the Pc cation. Direct photo-excitation of Pc did not show any detectable interaction between the excited state of Pc and the QD to which it is attached. An explanation is proposed, based on the suggestion that the energy of the lowest unoccupied molecular orbital (LUMO) of Pc is lower than the lower edge of the QD conduction band, while the energy of the highest occupied molecular orbital (HOMO) of Pc is sufficiently higher than the high energy edge of the QD valence band (VB), thus permitting hole transfer from the QD VB to the Pc HOMO after photo-excitation of QDs.
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Affiliation(s)
- M Arvani
- Department of Electronics and Communications Engineering, Tampere University of Technology, 33720 Tampere, Finland.
| | - K Virkki
- Department of Chemistry and Bioengineering, Tampere University of Technology, 33720 Tampere, Finland.
| | - F Abou-Chahine
- Department of Chemistry and Bioengineering, Tampere University of Technology, 33720 Tampere, Finland.
| | - A Efimov
- Department of Chemistry and Bioengineering, Tampere University of Technology, 33720 Tampere, Finland.
| | - A Schramm
- Department of Electronics and Communications Engineering, Tampere University of Technology, 33720 Tampere, Finland.
| | - N V Tkachenko
- Department of Chemistry and Bioengineering, Tampere University of Technology, 33720 Tampere, Finland.
| | - D Lupo
- Department of Electronics and Communications Engineering, Tampere University of Technology, 33720 Tampere, Finland.
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17
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Silvi S, Baroncini M, La Rosa M, Credi A. Interfacing Luminescent Quantum Dots with Functional Molecules for Optical Sensing Applications. Top Curr Chem (Cham) 2016; 374:65. [PMID: 27580893 DOI: 10.1007/s41061-016-0066-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 08/17/2016] [Indexed: 12/30/2022]
Abstract
Semiconductor quantum dots possess unique size-dependent electronic properties and are of high potential interest for the construction of functional nanodevices. Photoinduced electron- and energy-transfer processes between quantum dots and surface-bound molecular species open up attractive routes to implement chemical switching of luminescence, which is at the basis of luminescence sensing. In this article, we discuss the general principles underlying the rational design of this kind of multicomponent species. Successively, we illustrate a few prominent examples, taken from the recent literature, of luminescent chemosensors constructed by attaching molecular species to the surface of quantum dots.
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Affiliation(s)
- Serena Silvi
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, 40126, Bologna, Italy.
| | - Massimo Baroncini
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, 40126, Bologna, Italy
| | - Marcello La Rosa
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, via Selmi 2, 40126, Bologna, Italy
| | - Alberto Credi
- Dipartimento di Scienze e Tecnologie Agro-alimentari, Università di Bologna, viale Fanin 44, 40129, Bologna, Italy.
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Zeng P, Kirkwood N, Mulvaney P, Boldt K, Smith TA. Shell effects on hole-coupled electron transfer dynamics from CdSe/CdS quantum dots to methyl viologen. NANOSCALE 2016; 8:10380-10387. [PMID: 27139145 DOI: 10.1039/c6nr00168h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Electron transfer (ET) dynamics from the 1Se electron state in quasi-type II CdSe/CdS core/shell quantum dots (QDs) to adsorbed methyl viologen (MV(2+)) were measured using femtosecond transient absorption spectroscopy. The intrinsic ET rate kET was determined from the measured average number of ET-active MV(2+) per QD, which permits reliable comparisons of variant shell thickness and different hole states. The 1Se electron was extracted efficiently from the CdSe core, even for CdS shells up to 20 Å thick. The ET rate decayed exponentially from 10(10) to 10(9) s(-1) for increasing CdS shell thicknesses with an attenuation factor β≈ 0.13 Å(-1). We observed that compared to the ground state exciton 1Se1S3/2 the electron coupled to the 2S3/2 hot hole state exhibited slower ET rates for thin CdS shells. We attribute this behaviour to an Auger-assisted ET process (AAET), which depends on electron-hole coupling controlled by the CdS shell thickness.
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Affiliation(s)
- Peng Zeng
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia.
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Abstract
Understanding photoinduced charge transfer from nanomaterials is essential to the many applications of these materials. This review summarizes recent progress in understanding charge transfer from quantum dots (QDs), an ideal model system for investigating fundamental charge transfer properties of low-dimensional quantum-confined nanomaterials. We first discuss charge transfer from QDs to weakly coupled acceptors within the framework of Marcus nonadiabatic electron transfer (ET) theory, focusing on the dependence of ET rates on reorganization energy, electronic coupling, and driving force. Because of the strong electron-hole interaction, we show that ET from QDs should be described by the Auger-assisted ET model, which is significantly different from ET between molecules or from bulk semiconductor electrodes. For strongly quantum-confined QDs on semiconductor surfaces, the coupling can fall within the strong coupling limit, in which case the donor-acceptor interaction and ET properties can be described by the Newns-Anderson model of chemisorption. We also briefly discuss recent progress in controlling charge transfer properties in quantum-confined nanoheterostructures through wavefunction engineering and multiple exciton dissociation. Finally, we identify a few key areas for further research.
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Affiliation(s)
- Haiming Zhu
- Department of Chemistry, Emory University, Atlanta, Georgia 30322;
| | - Ye Yang
- Department of Chemistry, Emory University, Atlanta, Georgia 30322;
| | - Kaifeng Wu
- Department of Chemistry, Emory University, Atlanta, Georgia 30322;
| | - Tianquan Lian
- Department of Chemistry, Emory University, Atlanta, Georgia 30322;
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