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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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Hodges JM, Morse JR, Williams ME, Schaak RE. Microscopic Investigation of Chemoselectivity in Ag-Pt-Fe3O4 Heterotrimer Formation: Mechanistic Insights and Implications for Controlling High-Order Hybrid Nanoparticle Morphology. J Am Chem Soc 2015; 137:15493-500. [PMID: 26599998 DOI: 10.1021/jacs.5b10254] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Three-component hybrid nanoparticle heterotrimers, which are important multifunctional constructs that underpin diverse applications, are commonly synthesized by growing a third domain off of a two-component heterodimer seed. However, because heterodimer seeds expose two distinct surfaces that often can both support nucleation and growth, selectively targeting one particular surface is critical for exclusively accessing a desired configuration. Understanding and controlling nucleation and growth therefore enables the rational formation of high-order hybrid nanoparticles. Here, we report an in-depth microscopic investigation that probes the chemoselective addition of Ag to Pt-Fe3O4 heterodimer seeds to form Ag-Pt-Fe3O4 heterotrimers. We find that the formation of the Ag-Pt-Fe3O4 heterotrimers initiates with indiscriminate Ag nucleation onto both the Pt and Fe3O4 surfaces of Pt-Fe3O4, followed by surface diffusion and coalescence of Ag onto the Pt surface to form the Ag-Pt-Fe3O4 product. Control experiments reveal that the size of the Ag domain of Ag-Pt-Fe3O4 correlates with the overall surface area of the Pt-Fe3O4 seeds, which is consistent with the coalescence of Ag through a surface-mediated process and can also be exploited to tune the size of the Ag domain. Additionally, we observe that small iron oxide islands on the Pt surface of the Pt-Fe3O4 seeds, deposited during the formation of Pt-Fe3O4, define the morphology of the Ag domain, which in turn influences its optical properties. These results provide unprecedented microscopic insights into the pathway by which Ag-Pt-Fe3O4 heterotrimer nanoparticles form and uncover new design guidelines for the synthesis of high-order hybrid nanoparticles with precisely targeted morphologies and properties.
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Affiliation(s)
- James M Hodges
- Department of Chemistry and Materials Research Institute, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - James R Morse
- Department of Chemistry and Materials Research Institute, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Mary Elizabeth Williams
- Department of Chemistry and Materials Research Institute, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Raymond E Schaak
- Department of Chemistry and Materials Research Institute, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
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Jin C, Ma X, Zhang J, Huo Q, Dong R. Surface modification of Pt/C catalyst with Ag for electrooxidation of ethanol. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.08.121] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kitajima M, Narushima T, Kurashina T, Itakura AN, Takami S, Yamada A, Teraishi K, Miyamoto A. Stress inversion from initial tensile to compressive side during ultrathin oxide growth of the Si(100) surface. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:355007. [PMID: 23899747 DOI: 10.1088/0953-8984/25/35/355007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report the real-time observation of the stress change during sub-nanometer oxide growth on the Si(100) surface. Oxidation initially induced a rapid buildup of tensile stress up to -1.9 × 10(8) N m(-2) with an oxide thickness of 0.25 nm, followed by gradual compensation by a compressive stress. The compressive stress saturated at 5 × 10(7) N m(-2) for an oxide thickness of 1.2 nm. The analysis, assisted by theoretical study, indicates that the observed initial tensile stress is caused by oxygen bridge-bonding between the Si dimers. Atomistic model calculations considering mutually orthogonal orientations of the Si(100) surface structure reproduce the stress inversion from the tensile to the compressive side.
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Affiliation(s)
- Masahiro Kitajima
- Department of Applied Physics, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka 239-8686, Japan.
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Fillon A, Abadias G, Michel A, Jaouen C, Villechaise P. Influence of phase transformation on stress evolution during growth of metal thin films on silicon. PHYSICAL REVIEW LETTERS 2010; 104:096101. [PMID: 20366996 DOI: 10.1103/physrevlett.104.096101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Indexed: 05/29/2023]
Abstract
In situ stress measurements during two-dimensional growth of low mobility metal films on amorphous Si were used to demonstrate the impact of interface reactivity and phase transformation on stress evolution. Using Mo1-xSix films as examples, the results show that the tensile stress rise, which develops after the film has become crystalline, is correlated with an increase in lateral grain size. The origin of the tensile stress is attributed to the volume change resulting from the alloy crystallization, which occurs at a concentration-dependent critical thickness.
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Affiliation(s)
- A Fillon
- Institut P', CNRS-Université de Poitiers-ENSMA, Département Physique et Mécanique des Matériaux, SP2MI-Téléport 2, F86962 Futuroscope-Chasseneuil cedex, France
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Godin M, Tabard-Cossa V, Miyahara Y, Monga T, Williams PJ, Beaulieu LY, Bruce Lennox R, Grutter P. Cantilever-based sensing: the origin of surface stress and optimization strategies. NANOTECHNOLOGY 2010; 21:75501. [PMID: 20081290 DOI: 10.1088/0957-4484/21/7/075501] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Many interactions drive the adsorption of molecules on surfaces, all of which can result in a measurable change in surface stress. This article compares the contributions of various possible interactions to the overall induced surface stress for cantilever-based sensing applications. The surface stress resulting from adsorption-induced changes in the electronic density of the underlying surface is up to 2-4 orders of magnitude larger than that resulting from intermolecular electrostatic or Lennard-Jones interactions. We reveal that the surface stress associated with the formation of high quality alkanethiol self-assembled monolayers on gold surfaces is independent of the molecular chain length, supporting our theoretical findings. This provides a foundation for the development of new strategies for increasing the sensitivity of cantilever-based sensors for various applications.
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Affiliation(s)
- Michel Godin
- Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, ON, K1N 6N5, Canada.
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Mushrif SH, Rey AD. An integrated model for adsorption-induced strain in microporous solids. Chem Eng Sci 2009. [DOI: 10.1016/j.ces.2009.04.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Mironets O, Meyerheim HL, Tusche C, Stepanyuk VS, Soyka E, Zschack P, Hong H, Jeutter N, Felici R, Kirschner J. Direct evidence for mesoscopic relaxations in cobalt nanoislands on Cu(001). PHYSICAL REVIEW LETTERS 2008; 100:096103. [PMID: 18352728 DOI: 10.1103/physrevlett.100.096103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Indexed: 05/26/2023]
Abstract
Surface x-ray diffraction in combination with scanning tunneling microscopy and molecular dynamics calculations provide first quantitative evidence for unusually large relaxations in nanometer-sized Co islands deposited on Cu(001) at 170 K. These lead to sharply reduced interatomic Co distances as low as 2.36 A as compared to bulk Co (2.51 A) involving low symmetry Co adsorption sites. Our results prove the validity of the concept of mesoscopic mismatch which governs the strain relaxation of nanosized islands in general.
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Affiliation(s)
- O Mironets
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
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Zhang YF, Jia JF, Han TZ, Tang Z, Shen QT, Guo Y, Qiu ZQ, Xue QK. Band structure and oscillatory electron-phonon coupling of Pb thin films determined by atomic-layer-resolved quantum-well states. PHYSICAL REVIEW LETTERS 2005; 95:096802. [PMID: 16197236 DOI: 10.1103/physrevlett.95.096802] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Indexed: 05/04/2023]
Abstract
Using a low temperature growth method, we have prepared atomically flat Pb thin films over a wide range of film thickness on a Si-(111)-7 x 7 surface. The Pb film morphology and electronic structure are investigated in situ by scanning tunneling microscopy and angle-resolved photoemission spectroscopy. Well-defined and atomic-layer-resolved quantum-well states of the Pb films are used to determine the band structure and the electron-phonon coupling constant (lambda) of the films. We found an oscillatory behavior of lambda with an oscillation periodicity of two atomic layers. Almost all essential features in the Pb/Si(111) system, such as the growth mode, the oscillatory film stability, and the 9 monolayer envelope beating pattern, can be explained by our results in terms of the electron confinement in Pb films.
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Affiliation(s)
- Yan-Feng Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, The Chinese Academy of Sciences, Beijing 100080, China
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Rojas MI, Del Pópolo MG, Leiva EPM. Monte Carlo simulation of properties of monolayers and metal islands adsorbed on metallic (111) surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:4279-88. [PMID: 15969429 DOI: 10.1021/la036021z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
To obtain the surface stress changes deltasigma due to the adsorption of metal monolayers onto metallic surfaces, a new model derived from thermodynamic considerations is presented. Such a model is based on continuum Monte Carlo simulations with embedded atom method potentials in the canonical ensemble, and it is extended to consider the behavior on different islands adsorbed onto (111) substrate surfaces. Homoepitaxial and heteroepitaxial systems are studied. Pseudomorphic growth is not observed for small metal islands with considerable positive misfit with the substrate. Instead, the islands become compressed upon increase of their size. A simple model is proposed to interpolate between the misfits of atoms in small islands and the pseudomorphic behavior of the monolayer.
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Affiliation(s)
- Mariana I Rojas
- Unidad de Matemática y Física, Facultad de Ciencias Químicas, INFIQC, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina
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Investigating surface stress: Surface loss in ultrathin single-crystal silicon cantilevers. ACTA ACUST UNITED AC 2001. [DOI: 10.1116/1.1347040] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Mattsson TR, Metiu H. Nucleation and coarsening during epitaxy on a substrate subject to periodic strain: Spatial ordering and size uniformity. J Chem Phys 2000. [DOI: 10.1063/1.1322627] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Vakarin EV, Filippov AE, Badiali JP, Holovko MF. Structural rearrangement of solid surfaces due to competing adsorbate-substrate interactions. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 60:660-70. [PMID: 11969807 DOI: 10.1103/physreve.60.660] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/1998] [Indexed: 11/07/2022]
Abstract
Employing a generalized lattice gas theory and the Brownian dynamics simulation, we show that the competing displacive interaction in an adsorbate may cause a continuous distortive transition in the underlying substrate. The threshold for the transition is determined by the competition of the substrate rigidity and the quasielastic energy induced by the adsorbate. In the presence of a strong pinning and repulsive lateral interaction, the resulting structure appears as a compromise between the square lattice of the substrate and the hexagonal arrangement of the adsorbate. For hexagonal substrate lattices the simulation demonstrates that various adsorbate structures (from honeycomb lattices to quasicrystalline pentagonal configurations) may be observed, depending on the effective radii of interaction. Due to the long-ranged coupling the substrate may acquire a substructure induced by the adsorbate. This paper represents a generalization of the work published in Phys. Rev. Lett. 81, 3904 (1998).
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Affiliation(s)
- E V Vakarin
- Structure et Réactivité des Systèmes Interfaciaux, Université Pierre et Marie Curie, 4 Place Jussieu, 75230 Paris Cedex 05, France
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