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Frenkel N, Scharf E, Lubin G, Levi A, Panfil YE, Ossia Y, Planelles J, Climente JI, Banin U, Oron D. Two Biexciton Types Coexisting in Coupled Quantum Dot Molecules. ACS NANO 2023; 17:14990-15000. [PMID: 37459645 PMCID: PMC10416571 DOI: 10.1021/acsnano.3c03921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/12/2023] [Indexed: 08/09/2023]
Abstract
Coupled colloidal quantum dot molecules (CQDMs) are an emerging class of nanomaterials, manifesting two coupled emission centers and thus introducing additional degrees of freedom for designing quantum-dot-based technologies. The properties of multiply excited states in these CQDMs are crucial to their performance as quantum light emitters, but they cannot be fully resolved by existing spectroscopic techniques. Here we study the characteristics of biexcitonic species, which represent a rich landscape of different configurations essentially categorized as either segregated or localized biexciton states. To this end, we introduce an extension of Heralded Spectroscopy to resolve the different biexciton species in the prototypical CdSe/CdS CQDM system. By comparing CQDMs with single quantum dots and with nonfused quantum dot pairs, we uncover the coexistence and interplay of two distinct biexciton species: A fast-decaying, strongly interacting biexciton species, analogous to biexcitons in single quantum dots, and a long-lived, weakly interacting species corresponding to two nearly independent excitons. The two biexciton types are consistent with numerical simulations, assigning the strongly interacting species to two excitons localized at one side of the quantum dot molecule and the weakly interacting species to excitons segregated to the two quantum dot molecule sides. This deeper understanding of multiply excited states in coupled quantum dot molecules can support the rational design of tunable single- or multiple-photon quantum emitters.
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Affiliation(s)
- Nadav Frenkel
- Department
of Physics of Complex Systems, Weizmann
Institute of Science, Rehovot 7610001, Israel
| | - Einav Scharf
- Institute
of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Gur Lubin
- Department
of Physics of Complex Systems, Weizmann
Institute of Science, Rehovot 7610001, Israel
| | - Adar Levi
- Institute
of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yossef E. Panfil
- Institute
of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yonatan Ossia
- Institute
of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Josep Planelles
- Departament
de Quimica Fisica i Analitica, Universitat
Jaume I, E-12080 Castello de la Plana, Spain
| | - Juan I. Climente
- Departament
de Quimica Fisica i Analitica, Universitat
Jaume I, E-12080 Castello de la Plana, Spain
| | - Uri Banin
- Institute
of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Dan Oron
- Department
of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel
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2
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Zhou Y, Garoufalis CS, Baskoutas S, Zeng Z, Jia Y. Twisting Enabled Charge Transfer Excitons in Epitaxially Fused Quantum Dot Molecules. NANO LETTERS 2022; 22:4912-4918. [PMID: 35639504 DOI: 10.1021/acs.nanolett.2c01459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A heterojunction with type-II band alignment has long been considered as a prerequisite to realize charge transfer (CT) excitons which are highly appealing for exploration of quantum many-body phenomena, such as excitonic Bose-Einstein condensation and superfluidity. Herein, we have shown CT excitons can be activated via twisting in epitaxially fused heterodimer quantum dot (QD) molecules with quasi type-II band alignment, and even in QD homodimer molecules, therefore breaking the constraint of band alignment. The enabling power of twisting has been revealed. It modulates the orbital spatial localization toward charge separation that is mandatory for CT excitons. Meanwhile, it manifests an effective band offset that counterbalances the distinct many-body effects felt by excitons of different nature, thus ensuring the successful generation of CT excitons. The present work extends the realm of twistroincs into zero-dimensional materials and opens a novel pathway of manipulating the properties of QD materials and closely related molecular systems.
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Affiliation(s)
- Yamei Zhou
- Key Laboratory for Special Functional Materials of Ministry of Education, Collaborative Innovation Center of Nano Functional Materials and Applications, and School of Materials Science and Engineering, Henan University, Kaifeng, Henan 475001, China
| | | | - Sotirios Baskoutas
- Materials Science Department, University of Patras, 26504 Patras, Greece
| | - Zaiping Zeng
- Key Laboratory for Special Functional Materials of Ministry of Education, Collaborative Innovation Center of Nano Functional Materials and Applications, and School of Materials Science and Engineering, Henan University, Kaifeng, Henan 475001, China
| | - Yu Jia
- Key Laboratory for Special Functional Materials of Ministry of Education, Collaborative Innovation Center of Nano Functional Materials and Applications, and School of Materials Science and Engineering, Henan University, Kaifeng, Henan 475001, China
- International Laboratory for Quantum Functional Materials of Henan, and School of Physics and Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China
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3
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Zhang Z, Xia Y, Wan S, Yang D, Dong A. Confinement Assembly in Polymeric Micelles Enables Nanoparticle Superstructures with Tunable Molecular-Like Geometries. SMALL METHODS 2022; 6:e2200014. [PMID: 35142099 DOI: 10.1002/smtd.202200014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 01/19/2022] [Indexed: 06/14/2023]
Abstract
The self-assembly of a small number of nanoparticles into superstructures that mimic the geometry of molecules provides an unprecedented route for creating materials with precisely defined structures and potentially programmable functionalities. Such nanoparticle clusters (NPCs), also known as colloidal molecules, have a wide range of applications due to the decisive ensemble effect. Here, a universal and straightforward strategy is developed to construct NPCs with tunable molecular-like geometries by confining the self-assembly of hydrophobic nanoparticles within micelles formed by amphiphilic copolymers. It is found that confinement assembly of both spherical and anisotropic nanoparticles can lead to NPCs, the molecular-like conformation of which is widely tunable by adjusting the ratio between copolymers and nanoparticles. Mechanistic studies reveal the formation of large-vesicle intermediates along the path toward forming NPCs. This work establishes a facile and general strategy of assembling finite nanoparticles with precisely tunable geometries without introducing any directional interactions, which can accelerate the exploration of clustered superstructures toward broad applications.
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Affiliation(s)
- Zhebin Zhang
- State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai, 200433, China
| | - Yan Xia
- State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai, 200433, China
| | - Siyu Wan
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, China
| | - Dong Yang
- State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai, 200433, China
| | - Angang Dong
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, China
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4
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Cui J, Koley S, Panfil YE, Levi A, Ossia Y, Waiskopf N, Remennik S, Oded M, Banin U. Neck Barrier Engineering in Quantum Dot Dimer Molecules via Intraparticle Ripening. J Am Chem Soc 2021; 143:19816-19823. [PMID: 34791875 DOI: 10.1021/jacs.1c08863] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Coupled colloidal quantum dot (CQD) dimers represent a new class of artificial molecules composed of fused core/shell semiconductor nanocrystals. The electronic coupling and wave function hybridization are enabled by the formation of an epitaxial connection with a coherent lattice between the shells of the two neighboring quantum dots where the shell material and its dimensions dictate the quantum barrier characteristics for the charge carriers. Herein we introduce a colloidal approach to control the neck formation at the interface between the two CQDs in such artificial molecular constructs. This allows the tailoring of the neck barrier in prelinked homodimers formed via fusion of multifaceted wurtzite CdSe/CdS CQDs. The effects of reaction time, temperature, and excess ligands are studied. The neck filling process follows an intraparticle ripening mechanism at relatively mild reaction conditions while avoiding interparticle ripening. The degree of surface ligand passivation plays a key role in activating the surface atom diffusion to the neck region. The degree of neck filling strongly depends also on the initial relative orientation of the two CQDs, where homonymous plane attachment allows for facile neck growth, unlike the case of heteronymous plane attachment. Upon neck filling, the observed red-shift of the absorption and fluorescence measured both for ensemble and single dimers is assigned to enhanced hybridization of the confined wave function in CQD dimer molecules, as supported by quantum calculations. The fine-tuning of the particle interface introduced herein provides therefore a powerful tool to further control the extent of hybridization and coupling in CQD molecules.
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Affiliation(s)
- Jiabin Cui
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Somnath Koley
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yossef E Panfil
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Adar Levi
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yonatan Ossia
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Nir Waiskopf
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Sergei Remennik
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Meirav Oded
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Uri Banin
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.,The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Cassidy J, Yang M, Harankahage D, Porotnikov D, Moroz P, Razgoniaeva N, Ellison C, Bettinger J, Ehsan S, Sanchez J, Madry J, Khon D, Zamkov M. Tuning the Dimensionality of Excitons in Colloidal Quantum Dot Molecules. NANO LETTERS 2021; 21:7339-7346. [PMID: 34450018 DOI: 10.1021/acs.nanolett.1c02540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Electrically coupled quantum dots (QDs) can support unique optoelectronic properties arising from the superposition of single-particle excited states. Experimental methods for integrating colloidal QDs within the same nano-object, however, have remained elusive to the rational design. Here, we demonstrate a chemical strategy that allows for the assembling of colloidal QDs into coupled composites, where proximal interactions give rise to unique optoelectronic behavior. The assembly method employing "adhesive" surfactants was used to fabricate both homogeneous (e.g., CdS-CdS, PbS-PbS, CdSe-CdSe) and heterogeneous (e.g., PbS-CdS, CdS-CdSe) nanoparticle assemblies, exhibiting quasi-one-dimensional exciton fine structure. In addition, tunable mixing of single-particle exciton states was achieved for dimer-like assemblies of CdSe/CdS core-shell nanocrystals. The nanoparticle assembly mechanism was explained within the viscoelastic interaction theory adapted for molten-surface colloids. We expect that the present work will provide the synthetic and theoretical foundation needed for building assemblies of many inorganic nanocrystals.
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Affiliation(s)
- James Cassidy
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Mingrui Yang
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Dulanjan Harankahage
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Dmitry Porotnikov
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Pavel Moroz
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Natalia Razgoniaeva
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Cole Ellison
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Jacob Bettinger
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Shafqat Ehsan
- Department of Chemistry and Biochemistry, St. Mary's University, San Antonio, Texas 78228, United States
| | - John Sanchez
- Department of Chemistry and Biochemistry, St. Mary's University, San Antonio, Texas 78228, United States
| | - Jessica Madry
- Texas A&M University College of Medicine, Bryan, Texas 77807, United States
| | - Dmitriy Khon
- Department of Chemistry and Biochemistry, St. Mary's University, San Antonio, Texas 78228, United States
| | - Mikhail Zamkov
- The Center for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, United States
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