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Calvin JJ, Brewer AS, Crook MF, Kaufman TM, Alivisatos AP. Observation of negative surface and interface energies of quantum dots. Proc Natl Acad Sci U S A 2024; 121:e2307633121. [PMID: 38648471 PMCID: PMC11067453 DOI: 10.1073/pnas.2307633121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 03/21/2024] [Indexed: 04/25/2024] Open
Abstract
Surface energy is a fundamental property of materials and is particularly important in describing nanomaterials where atoms or molecules at the surface constitute a large fraction of the material. Traditionally, surface energy is considered to be a positive quantity, where atoms or molecules at the surface are less thermodynamically stable than their counterparts in the interior of the material because they have fewer bonds or interactions at the surface. Using calorimetric methods, we show that the surface energy is negative in some prototypical colloidal semiconductor nanocrystals, or quantum dots with organic ligand coatings. This implies that the surface atoms are more thermodynamically stable than those on the interior due to the strong bonds between these atoms and surfactant molecules, or ligands, that coat their surface. In addition, we extend this work to core/shell indium phosphide/zinc sulfide nanocrystals and show that the interfacial energy between these materials is highly thermodynamically favorable in spite of their large lattice mismatch. This work challenges many of the assumptions that have guided thinking about colloidal nanomaterial thermodynamics, investigates the fundamental stability of many technologically relevant colloidal nanomaterials, and paves the way for future experimental and theoretical work on nanocrystal thermodynamics.
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Affiliation(s)
- Jason J. Calvin
- Department of Chemistry, University of California, Berkeley, CA94720
- Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Amanda S. Brewer
- Department of Chemistry, University of California, Berkeley, CA94720
- Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Michelle F. Crook
- Department of Chemistry, University of California, Berkeley, CA94720
- Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Tierni M. Kaufman
- Department of Chemistry, University of California, Berkeley, CA94720
| | - A. Paul Alivisatos
- Department of Chemistry, University of California, Berkeley, CA94720
- Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
- Department of Materials Science and Engineering, University of California, Berkeley, CA94720
- Kavli Energy NanoScience Institute, University of California, Berkeley, CA94720
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Eagle F, Harvey S, Beck R, Li X, Gamelin DR, Cossairt BM. Enhanced Charge Transfer from Coinage Metal Doped InP Quantum Dots. ACS NANOSCIENCE AU 2023; 3:451-461. [PMID: 38144703 PMCID: PMC10740119 DOI: 10.1021/acsnanoscienceau.3c00029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/24/2023] [Accepted: 08/25/2023] [Indexed: 12/26/2023]
Abstract
This paper describes coinage-metal-doped InP quantum dots (QDs) as a platform for enhanced electron transfer to molecular acceptors relative to undoped QDs. A synthetic strategy is developed to prepare doped InP/ZnSe QDs. First-principles DFT calculations show that Ag+ and Cu+ dopants localize photoexcited holes while leaving electrons delocalized. This charge carrier wave function modulation is leveraged to enhance electron transfer to molecular acceptors by up to an order of magnitude. Examination of photoluminescence quenching data suggests that larger electron acceptors, such as anthraquinone and methyl viologen, bind to the QD surface in two ways: by direct adsorption to the surface and by adsorption following displacement of a weakly bound surface cation-ligand complex. Reactions with larger acceptors show the greatest increases in electron transfer between doped and undoped quantum dots, while smaller acceptors show smaller enhancements. Specifically, benzoquinone shows the smallest, followed by naphthoquinone and then methyl viologen and anthraquinone. These results demonstrate the benefits of dopant-induced excited-state carrier localization on photoinduced charge transfer and highlight design principles for improved implementation of quantum dots in photoredox catalysis.
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Affiliation(s)
- Forrest
W. Eagle
- Department of Chemistry, University
of Washington, Seattle, Washington 98195-1700, United States
| | - Samantha Harvey
- Department of Chemistry, University
of Washington, Seattle, Washington 98195-1700, United States
| | - Ryan Beck
- Department of Chemistry, University
of Washington, Seattle, Washington 98195-1700, United States
| | - Xiaosong Li
- Department of Chemistry, University
of Washington, Seattle, Washington 98195-1700, United States
| | - Daniel R. Gamelin
- Department of Chemistry, University
of Washington, Seattle, Washington 98195-1700, United States
| | - Brandi M. Cossairt
- Department of Chemistry, University
of Washington, Seattle, Washington 98195-1700, United States
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Van Avermaet H, Schiettecatte P, Hinz S, Giordano L, Ferrari F, Nayral C, Delpech F, Maultzsch J, Lange H, Hens Z. Full-Spectrum InP-Based Quantum Dots with Near-Unity Photoluminescence Quantum Efficiency. ACS NANO 2022; 16:9701-9712. [PMID: 35709384 DOI: 10.1021/acsnano.2c03138] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Photoluminescent color conversion by quantum dots (QDs) makes possible the formation of spectrum-on-demand light sources by combining blue LEDs with the light generated by a specific blend of QDs. Such applications, however, require a near-unity photoluminescence quantum efficiency since self-absorption magnifies disproportionally the impact of photon losses on the overall conversion efficiency. Here, we present a synthesis protocol for forming InP-based QDs with +90% quantum efficiency across the full visible spectrum from blue/cyan to red. The central features of our approach are as follows: (1) the formation of InP core QDs through one-batch-one-size reactions based on aminophosphine as the phosphorus precursor, (2) the introduction of a core/shell/shell InP/Zn(Se,S)/ZnS structure, and (3) the use of specific interfacial treatments, most notably the saturation of the ZnSe surface with zinc acetate prior to ZnS shell growth. Moreover, we adapted the composition of the Zn(Se,S) inner shell to attain the intended emission color while minimizing line broadening induced by the InP/ZnS lattice mismatch. The protocol is established by analysis of the QD composition and structure using multiple techniques, including solid-state nuclear magnetic resonance spectroscopy and Raman spectroscopy, and verified for reproducibility by having different researchers execute the same protocol. The realization of full-spectrum, +90% quantum efficiency will strongly facilitate research into light-matter interaction in general and luminescent color conversion in particular through InP-based QDs.
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Affiliation(s)
- Hannes Van Avermaet
- Physics and Chemistry of Nanostructures, Ghent University, Gent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent 9000, Belgium
| | - Pieter Schiettecatte
- Physics and Chemistry of Nanostructures, Ghent University, Gent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent 9000, Belgium
| | - Sandra Hinz
- Institute of Physical Chemistry, Universität Hamburg, Hamburg 20146, Germany
- Institute of Condensed Matter Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91058, Germany
| | - Luca Giordano
- Physics and Chemistry of Nanostructures, Ghent University, Gent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent 9000, Belgium
| | - Fabio Ferrari
- Laboratoire de Physique et Chimie des Nano-Objets, Université de Toulouse, CNRS, INSA, UPS, Toulouse CEDEX-4 31077, France
| | - Céline Nayral
- Laboratoire de Physique et Chimie des Nano-Objets, Université de Toulouse, CNRS, INSA, UPS, Toulouse CEDEX-4 31077, France
| | - Fabien Delpech
- Laboratoire de Physique et Chimie des Nano-Objets, Université de Toulouse, CNRS, INSA, UPS, Toulouse CEDEX-4 31077, France
| | - Janina Maultzsch
- Institute of Condensed Matter Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91058, Germany
| | - Holger Lange
- Institute of Physical Chemistry, Universität Hamburg, Hamburg 20146, Germany
| | - Zeger Hens
- Physics and Chemistry of Nanostructures, Ghent University, Gent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent 9000, Belgium
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Aikens CM, Jin R, Roy X, Tsukuda T. From atom-precise nanoclusters to superatom materials. J Chem Phys 2022; 156:170401. [PMID: 35525653 DOI: 10.1063/5.0095770] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Christine M Aikens
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, USA
| | - Rongchao Jin
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Xavier Roy
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Tatsuya Tsukuda
- Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Cui Z, Mei S, Wen Z, Yang D, Qin S, Xiong Z, Yang B, He H, Bao R, Qiu Y, Chen Y, Zhang W, Xie F, Xing G, Guo R. Synergistic Effect of Halogen Ions and Shelling Temperature on Anion Exchange Induced Interfacial Restructuring for Highly Efficient Blue Emissive InP/ZnS Quantum Dots. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2108120. [PMID: 35253372 DOI: 10.1002/smll.202108120] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/04/2022] [Indexed: 06/14/2023]
Abstract
InP quantum dots (QDs) have attracted much attention owing to their nontoxic properties and shown great potential in optoelectronic applications. Due to the surface defects and lattice mismatch, the interfacial structure of InP/ZnS QDs plays a significant role in their performance. Herein, the formation of In-S and Sx -In-P1-x interlayers through anion exchange at the shell-growth stage is revealed. More importantly, it is proposed that the composition of interface is dependent on the synergistic effect of halogen ions and shelling temperature. High shelling temperature contributes to the optical performance improvement resulting from the formation of interlayers, besides the thicker ZnS shell. Moreover, the effect relates to the halogen ions where I- presents more obvious enhancement than Br- and Cl- , owing to their different ability to coordinate with In dangling bonds, which are inclined to form In-S and Sx -In-P1-x bonds. Further, the anion exchange under I- -rich environment causes a blue-shift of emission wavelength with shelling temperature increasing, unobserved in a Cl- - or Br- -rich environment. It contributes to the preparation of highly efficient blue emissive InP/ZnS QDs with emission wavelength of 473 nm, photoluminescence quantum yield of ≈50% and full width at half maximum of 47 nm.
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Affiliation(s)
- Zhongjie Cui
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Shiliang Mei
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Zhuoqi Wen
- Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
| | - Dan Yang
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Shuaitao Qin
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Zhiyong Xiong
- Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
| | - Bobo Yang
- School of Science, Shanghai Institute of Technology, Shanghai, 201418, China
| | - Haiyang He
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Rui Bao
- Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
| | - Yi Qiu
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Yuanyuan Chen
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Wanlu Zhang
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Fengxian Xie
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
- Zhongshan-Fudan Joint Innovation Center, Zhongshan, 528437, China
| | - Guichuan Xing
- Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, 999078, China
| | - Ruiqian Guo
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
- Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
- Zhongshan-Fudan Joint Innovation Center, Zhongshan, 528437, China
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu City, 322000, China
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