Doping of Cr in Graphene Using Electron Beam Manipulation for Functional Defect Engineering

TL;DR

This paper demonstrates the controlled doping of graphene with chromium atoms using electron beam manipulation, enabling the creation of magnetic and semiconducting properties for potential electronic device applications.

Contribution

It introduces a novel electron beam technique for precise Cr doping in graphene, supported by first principles calculations to understand the process and properties.

Findings

Cr doping can induce magnetic and semiconducting behavior in graphene.

The method allows local control of dopant placement within the graphene lattice.

First principles calculations validate the synthesis pathways and properties of Cr-doped graphene.

Abstract

Chromium atoms in graphene have been proposed to exhibit magnetic moments and spin-selective conducting states depending on the local bonding geometry within the graphene structure, which could lead to interesting applications in spintronics. Despite this interest, there are few direct experimental reports of Cr dopants in graphene even though it is theorized to be stable. Here, we demonstrate the introduction of single Cr dopant atoms into the graphene lattice and onto graphene edges through the controlled use of a focused electron beam in a scanning transmission electron microscope. We show local control of doping locations and when coupled with targeted in situ milling during scanning of the e-beam, these strategies demonstrate an important component of the fabrication of tailored nanostructured devices in the electron microscope. The approach is validated with first principles calculations to understand synthesis pathways during fabrication and reveal the energetics and local properties of Cr atoms embedded in graphene; e.g., Cr doping can convert graphene into a magnetic and semiconducting material, which suggests Cr-doped graphene can be used as a building block for potential electronic devices and a means to construct them.