Impurity atom configurations in diamond and their visibility via scanning transmission electron microscopy imaging

TL;DR

This paper reviews impurity atom configurations in diamond, discusses their properties, and demonstrates how scanning transmission electron microscopy can visualize these structures, including presenting the first atomic resolution images of Er impurities.

Contribution

It provides the first atomic resolution images of impurity configurations in diamond and assesses their visibility via electron microscopy, bridging experimental observation with theoretical models.

Findings

Heavier dopants are easily discernible in electron microscopy images.

First atomic resolution images of substitutional Er in diamond are presented.

Simulations show a visibility window of over ±10 nm in defocus for dopants.

Abstract

Dispersed impurities in diamond present a flourishing platform for research in quantum informatics, spintronics and single phonon emitters. Based on the vast pool of experimental and theoretical work describing impurity atoms in diamond, we review the configurations by the chemical element discussing the relevant atomic configurations and most important properties. Dopant structures expand from single to co-doping configurations, also combined with carbon vacancies. Despite of their importance, not much is known about the exact atomic configurations associated with the dopant structures beyond computational models, partially due to difficulties in their microscopic observation. To assess the visibility of these structures, we carry out image simulations to show that the heavier dopants may be easily discernible in scanning transmission electron microscopy annular dark field images, with a window of visibility of up to over $\pm$ 10 nm in defocus. We further present the first atomic resolution images of an impurity atom configuration (substitutional Er atom) in the diamond lattice, confirmed by a comparison to the simulated images. Overall, our results demonstrate that there is a vast research field waiting for the microscopy community in resolving the exact atomic structure of various impurity atom configurations in diamond.