Signatures of distinct impurity configurations in atomic-resolution valence electron-energy-loss spectroscopy: Application to graphene
- Vanderbilt Univ., Nashville, TN (United States). Dept. of Physics and Astronomy; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division; Vanderbilt Univ., Nashville, TN (United States). Dept. of Physics and Astronomy
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
- National Univ of Singapore (Singapore). Dept. of Materials Science and Engineering
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
The detection and identification of impurities and other point defects in materials is a challenging task. Signatures for point defects are typically obtained using spectroscopies without spatial resolution. Here in this paper, we demonstrate the power of valence electron-energy-loss spectroscopy (VEELS) in an aberration-corrected scanning transmission-electron microscope (STEM) to provide energy-resolved and atomically resolved maps of electronic excitations of individual impurities which, combined with theoretical simulations, yield unique signatures of distinct bonding configurations of impurities. We report VEELS maps for isolated Si impurities in graphene, which are known to exist in two distinct configurations. We also report simulations of the maps, based on density functional theory and dynamical scattering theory, which agree with and provide direct interpretation of observed features. We show that theoretical VEELS maps exhibit distinct and unambiguous signatures for the threefold- and fourfold-coordinated configurations of Si impurities in different energy-loss windows, corresponding to impurity-induced bound states, resonances, and antiresonances. With the advent of new monochromators and detectors with high energy resolution and low signal-to-noise ratio, the present work ushers an atomically resolved STEM-based spectroscopy of individual impurities as an alternative to conventional spectroscopies for probing impurities and defects.
- Research Organization:
- Vanderbilt Univ., Nashville, TN (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- FG02-09ER46554; AC05-00OR22725; AC02-05CH11231
- OSTI ID:
- 1597791
- Alternate ID(s):
- OSTI ID: 1330483; OSTI ID: 1355872
- Journal Information:
- Physical Review B, Vol. 94, Issue 15; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Material structure, properties, and dynamics through scanning transmission electron microscopy
|
journal | April 2018 |
Substitutional Si impurities in monolayer hexagonal boron nitride
|
journal | August 2019 |
Atomic‐Scale Spectroscopic Imaging of the Extreme‐UV Optical Response of B‐ and N‐Doped Graphene
|
journal | May 2019 |
Substitutional Si impurities in monolayer hexagonal boron nitride | text | January 2019 |
Materials Structure, Properties and Dynamics through Scanning Transmission Electron Microscopy | text | January 2019 |
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