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Title: Resolving the Chemically Discrete Structure of Synthetic Borophene Polymorphs

Abstract

Atomically thin two-dimensional (2D) materials exhibit superlative properties dictated by their intralayer atomic structure, which is typically derived from a limited number of thermodynamically stable bulk layered crystals (e.g., graphene from graphite). The growth of entirely synthetic 2D crystals, those with no corresponding bulk allotrope, would circumvent this dependence upon bulk thermodynamics and substantially expand the phase space available for structure-property engineering of 2D materials. However, it remains unclear if synthetic 2D materials can exist as structurally and chemically distinct layers anchored by van der Waals (vdW) forces, as opposed to strongly bound adlayers. Here, we show that atomically thin sheets of boron (i.e., borophene) grown on the Ag(111) surface exhibit a vdW-like structure without a corresponding bulk allotrope. Using X-ray standing wave-excited X-ray photoelectron spectroscopy, the positions of boron in multiple chemical states are resolved with sub-angstrom spatial resolution, revealing that the borophene forms a single planar layer that is 2.4 angstrom above the unreconstructed Ag surface. Moreover, our results reveal that multiple borophene phases exhibit these characteristics, denoting a unique form of polymorphism consistent with recent predictions. Furthermore, this observation of synthetic borophene as chemically discrete from the growth substrate suggests that it is possible to engineer amore » much wider variety of 2D materials than those accessible through bulk layered crystal structures.« less

Authors:
 [1]; ORCiD logo [2];  [1];  [3];  [4]; ORCiD logo [1]; ORCiD logo [1]
  1. Northwestern Univ., Evanston, IL (United States)
  2. Northwestern Univ., Evanston, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Diamond Light Source, Didcot (United Kingdom)
  4. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES); US Department of the Navy, Office of Naval Research (ONR)
OSTI Identifier:
1482105
Grant/Contract Number:  
AC02-06CH11357
Resource Type:
Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 18; Journal Issue: 5; Journal ID: ISSN 1530-6984
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; boron; borophene; two-dimensional materials; x-ray photoelectron spectroscopy; x-ray standing wave

Citation Formats

Campbell, Gavin P., Mannix, Andrew J., Emery, Jonathan D., Lee, Tien -Lin, Guisinger, Nathan P., Hersam, Mark C., and Bedzyk, Michael J. Resolving the Chemically Discrete Structure of Synthetic Borophene Polymorphs. United States: N. p., 2018. Web. https://doi.org/10.1021/acs.nanolett.7b05178.
Campbell, Gavin P., Mannix, Andrew J., Emery, Jonathan D., Lee, Tien -Lin, Guisinger, Nathan P., Hersam, Mark C., & Bedzyk, Michael J. Resolving the Chemically Discrete Structure of Synthetic Borophene Polymorphs. United States. https://doi.org/10.1021/acs.nanolett.7b05178
Campbell, Gavin P., Mannix, Andrew J., Emery, Jonathan D., Lee, Tien -Lin, Guisinger, Nathan P., Hersam, Mark C., and Bedzyk, Michael J. Fri . "Resolving the Chemically Discrete Structure of Synthetic Borophene Polymorphs". United States. https://doi.org/10.1021/acs.nanolett.7b05178. https://www.osti.gov/servlets/purl/1482105.
@article{osti_1482105,
title = {Resolving the Chemically Discrete Structure of Synthetic Borophene Polymorphs},
author = {Campbell, Gavin P. and Mannix, Andrew J. and Emery, Jonathan D. and Lee, Tien -Lin and Guisinger, Nathan P. and Hersam, Mark C. and Bedzyk, Michael J.},
abstractNote = {Atomically thin two-dimensional (2D) materials exhibit superlative properties dictated by their intralayer atomic structure, which is typically derived from a limited number of thermodynamically stable bulk layered crystals (e.g., graphene from graphite). The growth of entirely synthetic 2D crystals, those with no corresponding bulk allotrope, would circumvent this dependence upon bulk thermodynamics and substantially expand the phase space available for structure-property engineering of 2D materials. However, it remains unclear if synthetic 2D materials can exist as structurally and chemically distinct layers anchored by van der Waals (vdW) forces, as opposed to strongly bound adlayers. Here, we show that atomically thin sheets of boron (i.e., borophene) grown on the Ag(111) surface exhibit a vdW-like structure without a corresponding bulk allotrope. Using X-ray standing wave-excited X-ray photoelectron spectroscopy, the positions of boron in multiple chemical states are resolved with sub-angstrom spatial resolution, revealing that the borophene forms a single planar layer that is 2.4 angstrom above the unreconstructed Ag surface. Moreover, our results reveal that multiple borophene phases exhibit these characteristics, denoting a unique form of polymorphism consistent with recent predictions. Furthermore, this observation of synthetic borophene as chemically discrete from the growth substrate suggests that it is possible to engineer a much wider variety of 2D materials than those accessible through bulk layered crystal structures.},
doi = {10.1021/acs.nanolett.7b05178},
journal = {Nano Letters},
number = 5,
volume = 18,
place = {United States},
year = {2018},
month = {4}
}

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Works referenced in this record:

Synthesis of borophenes: Anisotropic, two-dimensional boron polymorphs
journal, December 2015


Experimental realization of two-dimensional boron sheets
journal, March 2016

  • Feng, Baojie; Zhang, Jin; Zhong, Qing
  • Nature Chemistry, Vol. 8, Issue 6
  • DOI: 10.1038/nchem.2491

The rise of graphene
journal, March 2007

  • Geim, A. K.; Novoselov, K. S.
  • Nature Materials, Vol. 6, Issue 3, p. 183-191
  • DOI: 10.1038/nmat1849

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides
journal, November 2012

  • Wang, Qing Hua; Kalantar-Zadeh, Kourosh; Kis, Andras
  • Nature Nanotechnology, Vol. 7, Issue 11, p. 699-712
  • DOI: 10.1038/nnano.2012.193

Two-Dimensional Boron Monolayers Mediated by Metal Substrates
journal, September 2015

  • Zhang, Zhuhua; Yang, Yang; Gao, Guoying
  • Angewandte Chemie International Edition, Vol. 54, Issue 44
  • DOI: 10.1002/anie.201505425

Novel Precursors for Boron Nanotubes: The Competition of Two-Center and Three-Center Bonding in Boron Sheets
journal, September 2007


Polymorphism of Two-Dimensional Boron
journal, April 2012

  • Penev, Evgeni S.; Bhowmick, Somnath; Sadrzadeh, Arta
  • Nano Letters, Vol. 12, Issue 5
  • DOI: 10.1021/nl3004754

Two-Dimensional Boron Monolayer Sheets
journal, July 2012


Polyphony in B flat
journal, April 2016

  • Zhang, Zhuhua; Penev, Evgeni S.; Yakobson, Boris I.
  • Nature Chemistry, Vol. 8, Issue 6
  • DOI: 10.1038/nchem.2521

Graphene on Ir(111): Physisorption with Chemical Modulation
journal, July 2011


Substrate-Induced Nanoscale Undulations of Borophene on Silver
journal, September 2016


Synthesis and chemistry of elemental 2D materials
journal, January 2017

  • Mannix, Andrew J.; Kiraly, Brian; Hersam, Mark C.
  • Nature Reviews Chemistry, Vol. 1, Issue 2
  • DOI: 10.1038/s41570-016-0014

Dirac Fermions in Borophene
journal, March 2017


Potential Energy Landscape for Hot Electrons in Periodically Nanostructured Graphene
journal, July 2010


Angular distribution of the photoelectron yield excited by two coherently coupled photon beams
journal, September 1989


X-ray standing wave study of iodine on Ge(111)
journal, October 1989


Solution to the Surface Registration Problem Using X-Ray Standing Waves
journal, August 1982


Direct evidence of metallic bands in a monolayer boron sheet
journal, July 2016


Can Two-Dimensional Boron Superconduct?
journal, March 2016


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    • Li, Dengfeng; Gao, Junfeng; Cheng, Peng
    • Advanced Functional Materials, Vol. 30, Issue 8
    • DOI: 10.1002/adfm.201904349

    Geometric imaging of borophene polymorphs with functionalized probes
    journal, April 2019


    Freestanding Borophene and Its Hybrids
    journal, May 2019

    • Ranjan, Pranay; Sahu, Tumesh Kumar; Bhushan, Rebti
    • Advanced Materials, Vol. 31, Issue 27
    • DOI: 10.1002/adma.201900353