Prospects for detecting individual defect centers using spatially resolved electron energy loss spectroscopy
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2019-10-14 |
| Journal | Physical review. B./Physical review. B |
| Authors | David Kordahl, Lance W.Q. Xu, Shery L. Y. Chang, Christian Dwyer |
| Institutions | Arizona State University |
| Citations | 5 |
Abstract
Section titled āAbstractāWe consider the prospects of locating and characterizing individual defect centers in bulk materials using electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM). We simulate STEM-EELS maps for two important defect centers in diamond, namely, the negatively charged nitrogen-vacancy defect and the neutral silicon-vacancy defect. We use density-functional theory to compute the defect electronic structure and a M\o{}ller potential formalism to compute the inelastic electron scattering. Our results indicate that it should be possible to use STEM-EELS to obtain the transverse locations of these defects to within about 1 nm. We calculate the plane-wave scattering cross sections for these individual defects to be of the order of ${10}^{\ensuremath{-}4}$ \AA{}${}^{2}$, which indicates that the EELS signals should be within detectable limits. Calculated spectral maps and scattering cross sections are given as a function of the defect orientation, and we show that the results can be interpreted using a tight-binding description of the defect electronic structure.