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Zhao Q, Gouget G, Guo J, Yang S, Zhao T, Straus DB, Qian C, Oh N, Wang H, Murray CB, Kagan CR. Enhanced Carrier Transport in Strongly Coupled, Epitaxially Fused CdSe Nanocrystal Solids. NANO LETTERS 2021; 21:3318-3324. [PMID: 33792310 DOI: 10.1021/acs.nanolett.1c00860] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Strongly coupled, epitaxially fused colloidal nanocrystal (NC) solids are promising solution-processable semiconductors to realize optoelectronic devices with high carrier mobilities. Here, we demonstrate sequential, solid-state cation exchange reactions to transform epitaxially connected PbSe NC thin films into Cu2Se nanostructured thin-film intermediates and then successfully to achieve zinc-blende, CdSe NC solids with wide epitaxial necking along {100} facets. Transient photoconductivity measurements probe carrier transport at nanometer length scales and show a photoconductance of 0.28(1) cm2 V-1 s-1, the highest among CdSe NC solids reported. Atomic-layer deposition of a thin Al2O3 layer infiltrates and protects the structure from fusing into a polycrystalline thin film during annealing and further improves the photoconductance to 1.71(5) cm2 V-1 s-1 and the diffusion length to 760 nm. We fabricate field-effect transistors to study carrier transport at micron length scales and realize high electron mobilities of 35(3) cm2 V-1 s-1 with on-off ratios of 106 after doping.
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2
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Ondry JC, Philbin JP, Lostica M, Rabani E, Alivisatos AP. Colloidal Synthesis Path to 2D Crystalline Quantum Dot Superlattices. ACS NANO 2021; 15:2251-2262. [PMID: 33377761 DOI: 10.1021/acsnano.0c07202] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
By combining colloidal nanocrystal synthesis, self-assembly, and solution phase epitaxial growth techniques, we developed a general method for preparing single dot thick atomically attached quantum dot (QD) superlattices with high-quality translational and crystallographic orientational order along with state-of-the-art uniformity in the attachment thickness. The procedure begins with colloidal synthesis of hexagonal prism shaped core/shell QDs (e.g., CdSe/CdS), followed by liquid subphase self-assembly and immobilization of superlattices on a substrate. Solution phase epitaxial growth of additional semiconductor material fills in the voids between the particles, resulting in a QD-in-matrix structure. The photoluminescence emission spectra of the QD-in-matrix structure retains characteristic 0D electronic confinement. Importantly, annealing of the resulting structures removes inhomogeneities in the QD-QD inorganic bridges, which our atomistic electronic structure calculations demonstrate would otherwise lead to Anderson-type localization. The piecewise nature of this procedure allows one to independently tune the size and material of the QD core, shell, QD-QD distance, and the matrix material. These four choices can be tuned to control many properties (degree of quantum confinement, quantum coupling, band alignments, etc.) depending on the specific applications. Finally, cation exchange reactions can be performed on the final QD-in-matrix, as demonstrated herein with a CdSe/CdS to HgSe/HgS conversion.
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Affiliation(s)
- Justin C Ondry
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Kavli Energy NanoScience Institute, Berkeley, California 94720, United States
| | - John P Philbin
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Michael Lostica
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Eran Rabani
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv, Israel 69978
| | - A Paul Alivisatos
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Kavli Energy NanoScience Institute, Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States
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3
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Unravelling three-dimensional adsorption geometries of PbSe nanocrystal monolayers at a liquid-air interface. Commun Chem 2020; 3:28. [PMID: 36703462 PMCID: PMC9814399 DOI: 10.1038/s42004-020-0275-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/07/2020] [Indexed: 01/29/2023] Open
Abstract
The adsorption, self-organization and oriented attachment of PbSe nanocrystals (NCs) at liquid-air interfaces has led to remarkable nanocrystal superlattices with atomic order and a superimposed nanoscale geometry. Earlier studies examined the NC self-organization at the suspension/air interface with time-resolved in-situ X-ray scattering. Upon continuous evaporation of the solvent, the NC interfacial layer will finally contact the (ethylene glycol) liquid substrate on which the suspension was casted. In order to obtain structural information on the NC organization at this stage of the process, we examined the ethylene glycol/NC interface in detail for PbSe NCs of different sizes, combining in-situ grazing-incidence small-and-wide-angle X-ray scattering (GISAXS/GIWAXS), X-ray reflectivity (XRR) and analytical calculations of the adsorption geometry of these NCs. Here, we observe in-situ three characteristic adsorption geometries varying with the NC size. Based on the experimental evidence and simulations, we reveal fully three-dimensional arrangements of PbSe nanocrystals at the ethylene glycol-air interface with and without the presence of rest amounts of toluene.
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Abelson A, Qian C, Salk T, Luan Z, Fu K, Zheng JG, Wardini JL, Law M. Collective topo-epitaxy in the self-assembly of a 3D quantum dot superlattice. NATURE MATERIALS 2020; 19:49-55. [PMID: 31611669 DOI: 10.1038/s41563-019-0485-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 08/15/2019] [Indexed: 05/25/2023]
Abstract
Epitaxially fused colloidal quantum dot (QD) superlattices (epi-SLs) may enable a new class of semiconductors that combine the size-tunable photophysics of QDs with bulk-like electronic performance, but progress is hindered by a poor understanding of epi-SL formation and surface chemistry. Here we use X-ray scattering and correlative electron imaging and diffraction of individual SL grains to determine the formation mechanism of three-dimensional PbSe QD epi-SL films. We show that the epi-SL forms from a rhombohedrally distorted body centred cubic parent SL via a phase transition in which the QDs translate with minimal rotation (~10°) and epitaxially fuse across their {100} facets in three dimensions. This collective epitaxial transformation is atomically topotactic across the 103-105 QDs in each SL grain. Infilling the epi-SLs with alumina by atomic layer deposition greatly changes their electrical properties without affecting the superlattice structure. Our work establishes the formation mechanism of three-dimensional QD epi-SLs and illustrates the critical importance of surface chemistry to charge transport in these materials.
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Affiliation(s)
- Alex Abelson
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA, USA
| | - Caroline Qian
- Department of Chemical and Biomolecular Engineering, University of California, Irvine, Irvine, CA, USA
| | - Trenton Salk
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA
| | - Zhongyue Luan
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA, USA
| | - Kan Fu
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA, USA
| | - Jian-Guo Zheng
- Irvine Materials Research Institute, University of California, Irvine, Irvine, CA, USA
| | - Jenna L Wardini
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA, USA
| | - Matt Law
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA, USA.
- Department of Chemical and Biomolecular Engineering, University of California, Irvine, Irvine, CA, USA.
- Department of Chemistry, University of California, Irvine, Irvine, CA, USA.
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5
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Mukharamova N, Lapkin D, Zaluzhnyy IA, André A, Lazarev S, Kim YY, Sprung M, Kurta RP, Schreiber F, Vartanyants IA, Scheele M. Revealing Grain Boundaries and Defect Formation in Nanocrystal Superlattices by Nanodiffraction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1904954. [PMID: 31729151 DOI: 10.1002/smll.201904954] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 10/18/2019] [Indexed: 05/13/2023]
Abstract
X-ray nanodiffraction is applied to study the formation and correlation of domain boundaries in mesocrystalline superlattices of PbS nanocrystals with face-centered cubic structure. Each domain of the superlattice can be described with one of two mesocrystalline polymorphs with different orientational orders. Close to a grain boundary, the lattice constant decreases and the superlattice undergoes an out-of-plane rotation, while the orientation of the nanocrystals with respect to the superlattice remains unchanged. These findings are explained with the release of stress on the expense of specific nanocrystal-substrate interactions. The fact that correlations between adjacent nanocrystals are found to survive the structural changes at most grain boundaries implies that the key to nanocrystal superlattices with macroscopic domain sizes are strengthened interactions with the substrate.
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Affiliation(s)
- Nastasia Mukharamova
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany
| | - Dmitry Lapkin
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany
| | - Ivan A Zaluzhnyy
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany
- National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe shosse 31, 115409, Moscow, Russia
| | - Alexander André
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Sergey Lazarev
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany
- Tomsk Open Laboratory for Material Inspection (TOLMI), National Research Tomsk Polytechnic University (TPU), pr. Lenina 30, 634050, Tomsk, Russia
| | - Young Yong Kim
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany
| | - Michael Sprung
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany
| | - Ruslan P Kurta
- European XFEL GmbH, Holzkoppel 4, D-22869, Schenefeld, Germany
| | - Frank Schreiber
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076, Tübingen, Germany
- Center for Light-Matter Interaction, Sensors & Analytics LISA+, University of Tübingen, Auf der Morgenstelle 15, 72076, Tübingen, Germany
| | - Ivan A Vartanyants
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany
- National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe shosse 31, 115409, Moscow, Russia
| | - Marcus Scheele
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
- Center for Light-Matter Interaction, Sensors & Analytics LISA+, University of Tübingen, Auf der Morgenstelle 15, 72076, Tübingen, Germany
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6
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McCray ARC, Savitzky BH, Whitham K, Hanrath T, Kourkoutis LF. Orientational Disorder in Epitaxially Connected Quantum Dot Solids. ACS NANO 2019; 13:11460-11468. [PMID: 31502825 DOI: 10.1021/acsnano.9b04951] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Periodic arrays of strongly coupled colloidal quantum dots (QDs) may enable unprecedented control of electronic band structure through manipulation of QD size, shape, composition, spacing, and assembly geometry. This includes the possibilities of precisely engineered bandgaps and charge carrier mobilities, as well as remarkable behaviors such as metal-insulator transitions, massless carriers, and topological states. However, experimental realization of these theoretically predicted electronic structures is presently limited by structural disorder. Here, we use aberration-corrected scanning transmission electron microscopy to precisely quantify the orientational disorder of epitaxially connected QD films. In spite of coherent atomic connectivity between nearest neighbor QDs, we find misalignment persists with a standard deviation of 1.9°, resulting in significant bending strain localized to the adjoining necks. We observe and quantify a range of out-of-plane particle orientations over thousands of QDs and correlate the in-plane and out-of-plane misalignments, finding QDs misoriented out-of-plane display a statistically greater misalignment with respect to their in-plane neighbors as well. Using the bond orientational order metric ψ4, we characterize the 4-fold symmetry and introduce a quantification of the local superlattice (SL) orientation. This enables direct comparison between local orientational order in the SL and atomic lattice (AL). We find significantly larger variations in the SL orientation and a statistically robust but locally highly variable correlation between the orientations of the two differently scaled lattices. Distinct AL and SL behaviors are observed about a grain boundary, with a sharp boundary in the AL orientations, but a more smooth transition in the SL, facilitated by lattice deformation between the neighboring grains. Coupling between the AL and SL is a fundamental driver of film growth, and these results suggest nontrivial underlying mechanics, implying that simplified models of epitaxial attachment may be insufficient to understand QD growth and disorder when oriented attachment and superlattice growth occur in concert.
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Affiliation(s)
- Arthur R C McCray
- School of Applied and Engineering Physics , Cornell University , Ithaca , New York 14853 , United States
| | - Benjamin H Savitzky
- Department of Physics , Cornell University , Ithaca , New York 14853 , United States
| | - Kevin Whitham
- Department of Materials Science and Engineering , Cornell University , Ithaca , New York 14853 , United States
| | - Tobias Hanrath
- School of Chemical and Biomolecular Engineering , Cornell University , Ithaca , New York 14853 , United States
| | - Lena F Kourkoutis
- School of Applied and Engineering Physics , Cornell University , Ithaca , New York 14853 , United States
- Kavli Institute for Nanoscale Science , Cornell University , Ithaca , New York 14853 , United States
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7
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Greenberg BL, Robinson ZL, Ayino Y, Held JT, Peterson TA, Mkhoyan KA, Pribiag VS, Aydil ES, Kortshagen UR. Metal-insulator transition in a semiconductor nanocrystal network. SCIENCE ADVANCES 2019; 5:eaaw1462. [PMID: 31467972 PMCID: PMC6707780 DOI: 10.1126/sciadv.aaw1462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 07/15/2019] [Indexed: 06/01/2023]
Abstract
Many envisioned applications of semiconductor nanocrystals (NCs), such as thermoelectric generators and transparent conductors, require metallic (nonactivated) charge transport across an NC network. Although encouraging signs of metallic or near-metallic transport have been reported, a thorough demonstration of nonzero conductivity, σ, in the 0 K limit has been elusive. Here, we examine the temperature dependence of σ of ZnO NC networks. Attaining both higher σ and lower temperature than in previous studies of ZnO NCs (T as low as 50 mK), we observe a clear transition from the variable-range hopping regime to the metallic regime. The critical point of the transition is distinctly marked by an unusual power law close to σ ∝ T 1/5. We analyze the critical conductivity data within a quantum critical scaling framework and estimate the metal-insulator transition (MIT) criterion in terms of the free electron density, n, and interparticle contact radius, ρ.
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Affiliation(s)
| | - Zachary L. Robinson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Yilikal Ayino
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Jacob T. Held
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, USA
| | - Timothy A. Peterson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - K. Andre Mkhoyan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, USA
| | - Vlad S. Pribiag
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Eray S. Aydil
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, USA
| | - Uwe R. Kortshagen
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, USA
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8
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Balazs DM, Matysiak BM, Momand J, Shulga AG, Ibáñez M, Kovalenko MV, Kooi BJ, Loi MA. Electron Mobility of 24 cm 2 V -1 s -1 in PbSe Colloidal-Quantum-Dot Superlattices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802265. [PMID: 30069938 DOI: 10.1002/adma.201802265] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/07/2018] [Indexed: 05/28/2023]
Abstract
Colloidal quantum dots (CQDs) are nanoscale building blocks for bottom-up fabrication of semiconducting solids with tailorable properties beyond the possibilities of bulk materials. Achieving ordered, macroscopic crystal-like assemblies has been in the focus of researchers for years, since it would allow exploitation of the quantum-confinement-based electronic properties with tunable dimensionality. Lead-chalcogenide CQDs show especially strong tendencies to self-organize into 2D superlattices with micrometer-scale order, making the array fabrication fairly simple. However, most studies concentrate on the fundamentals of the assembly process, and none have investigated the electronic properties and their dependence on the nanoscale structure induced by different ligands. Here, it is discussed how different chemical treatments on the initial superlattices affect the nanostructure, the optical, and the electronic-transport properties. Transistors with average two-terminal electron mobilities of 13 cm2 V-1 s-1 and contactless mobility of 24 cm2 V-1 s-1 are obtained for small-area superlattice field-effect transistors. Such mobility values are the highest reported for CQD devices wherein the quantum confinement is substantially present and are comparable to those reported for heavy sintering. The considerable mobility with the simultaneous preservation of the optical bandgap displays the vast potential of colloidal QD superlattices for optoelectronic applications.
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Affiliation(s)
- Daniel M Balazs
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands
| | - Bartosz M Matysiak
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands
| | - Jamo Momand
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands
| | - Artem G Shulga
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands
| | - Maria Ibáñez
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, 8093, Switzerland
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, 8600, Switzerland
| | - Maksym V Kovalenko
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, 8093, Switzerland
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, 8600, Switzerland
| | - Bart J Kooi
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands
| | - Maria Antonietta Loi
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands
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9
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van Overbeek C, Peters JL, van Rossum SAP, Smits M, van Huis MA, Vanmaekelbergh D. Interfacial Self-Assembly and Oriented Attachment in the Family of PbX (X = S, Se, Te) Nanocrystals. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2018; 122:12464-12473. [PMID: 29930743 PMCID: PMC6004561 DOI: 10.1021/acs.jpcc.8b01876] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/11/2018] [Indexed: 05/26/2023]
Abstract
The realization of materials with new optoelectronic properties draws much scientific attention toward the field of nanocrystal superstructures. Low-dimensional superstructures created by interfacial assembly and oriented attachment of PbSe nanocrystals are a striking example because theory showed that PbSe sheets with a honeycomb geometry possess non-trivial flat bands and Dirac cones in the valence and conduction bands. Here, we report on the formation of one-dimensional linear and zigzag structures and two-dimensional (2D) square and honeycomb structures for the entire lead chalcogenide family: PbX (X = S, Se, Te). We observe that PbTe, with a lower bulk melting temperature and enthalpy of formation than those of PbSe, shows a higher nanocrystal surface reactivity, such that the surface must be passivated and the reaction conditions moderated to obtain reasonably ordered superstructures. The present findings constitute a step forward in the realization of a larger family of atomically coherent 2D superstructures with variable IV-VI and II-VI compositions and with electronic properties dictated by the nanogeometry.
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10
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Ondry JC, Hauwiller MR, Alivisatos AP. Dynamics and Removal Pathway of Edge Dislocations in Imperfectly Attached PbTe Nanocrystal Pairs: Toward Design Rules for Oriented Attachment. ACS NANO 2018; 12:3178-3189. [PMID: 29470056 DOI: 10.1021/acsnano.8b00638] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Using in situ high-resolution TEM, we study the structure and dynamics of well-defined edge dislocations in imperfectly attached PbTe nanocrystals. We identify that attachment of PbTe nanocrystals on both {100} and {110} facets gives rise to b = a/2⟨110⟩ edge dislocations. Based on the Burgers vector of individual dislocations, we can identify the glide plane of the dislocations. We observe that defects in particles attached on {100} facets have glide planes that quickly intersect the surface, and HRTEM movies show that the defects follow the glide plane to the surface. For {110} attached particles, the glide plane is collinear with the attachment direction, which does not provide an easy path for the dislocation to reach the surface. Indeed, HRTEM movies of dislocations for {110} attached particles show that defect removal is much slower. Further, we observe conversion from pure edge dislocations in imperfectly attached particles to dislocations with mixed edge and screw character, which has important implications for crystal growth. Finally, we observe that dislocations initially closer to the surface have a higher speed of removal, consistent with the strong dislocation free surface attractive force. Our results provide important design rules for defect-free attachment of preformed nanocrystals into epitaxial assemblies.
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Affiliation(s)
- Justin C Ondry
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Matthew R Hauwiller
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - A Paul Alivisatos
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute , Berkeley , California 94720 , United States
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11
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Greenwood AR, Vörös M, Giberti F, Galli G. Emergent Electronic and Dielectric Properties of Interacting Nanoparticles at Finite Temperature. NANO LETTERS 2018; 18:255-261. [PMID: 29227689 DOI: 10.1021/acs.nanolett.7b04047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Lead chalcogenide nanoparticle solids have been successfully integrated into certified solar cells and represent promising platforms for the design of novel photoabsorbers for photoelectrochemical cells. While much attention has been drawn to improving efficiency and device performance through altering the character of the individual nanoparticles, the role of interactions between nanoparticles is not yet well-understood. Using first-principles molecular dynamics and electronic structure calculations, we investigated the combined effect of temperature and interaction on functionalized lead chalcogenide nanoparticles (NPs). Here, we show that at finite temperature, interacting NPs are dynamical dipolar systems, with the average values of dipole moments and polarizabilities substantially increased with respect to those of the isolated building blocks. In addition, we show that the interacting NPs exhibit slightly smaller fundamental gaps that decrease as a function of temperature and that the radiative lifetimes of both the isolated NPs and the solids are greatly reduced at finite temperature compared to T = 0. Finally, we present a critical discussion of various results reported in the literature for the values of dipole moments of nanoparticles.
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Affiliation(s)
- Arin R Greenwood
- Institute for Molecular Engineering, The University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Márton Vörös
- Argonne National Laboratory , 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Federico Giberti
- Institute for Molecular Engineering, The University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Giulia Galli
- Institute for Molecular Engineering, The University of Chicago , 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
- Argonne National Laboratory , 9700 South Cass Avenue, Argonne, Illinois 60439, United States
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