First Principles Study of Electronic Structure and Transport in Graphene Grain Boundaries

Fuente: arXiv
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Autori principali: Lorentzen, Aleksander Bach, Gao, Fei, Bøggild, Peter, Jauho, Antti-Pekka, Brandbyge, Mads
Natura: Preprint
Pubblicazione: 2024
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author Lorentzen, Aleksander Bach
Gao, Fei
Bøggild, Peter
Jauho, Antti-Pekka
Brandbyge, Mads
author_facet Lorentzen, Aleksander Bach
Gao, Fei
Bøggild, Peter
Jauho, Antti-Pekka
Brandbyge, Mads
contents Grain boundaries play a major role for electron transport in graphene sheets grown by chemical vapor deposition. Here we investigate the electronic structure and transport properties of idealized graphene grain boundaries (GBs) in bi-crystals using first principles density functional theory (DFT) and non-equilibrium Greens functions (NEGF). We generated 150 different grain boundaries using an automated workflow where their geometry is relaxed with DFT. We find that the GBs generally show a quasi-1D bandstructure along the GB. We group the GBs in four classes based on their conductive properties: transparent, opaque, insulating, and spin-polarizing and show how this is related to angular mismatch, quantum mechanical interference, and out-of-plane buckling. Especially, we find that spin-polarization in the GB correlates with out-of-plane buckling. We further investigate the characteristics of these classes in simulated scanning tunnelling spectroscopy and diffusive transport along the GB which demonstrate how current can be guided along the GB.
format Preprint
id arxiv_https___arxiv_org_abs_2401_06556
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle First Principles Study of Electronic Structure and Transport in Graphene Grain Boundaries
Lorentzen, Aleksander Bach
Gao, Fei
Bøggild, Peter
Jauho, Antti-Pekka
Brandbyge, Mads
Mesoscale and Nanoscale Physics
Grain boundaries play a major role for electron transport in graphene sheets grown by chemical vapor deposition. Here we investigate the electronic structure and transport properties of idealized graphene grain boundaries (GBs) in bi-crystals using first principles density functional theory (DFT) and non-equilibrium Greens functions (NEGF). We generated 150 different grain boundaries using an automated workflow where their geometry is relaxed with DFT. We find that the GBs generally show a quasi-1D bandstructure along the GB. We group the GBs in four classes based on their conductive properties: transparent, opaque, insulating, and spin-polarizing and show how this is related to angular mismatch, quantum mechanical interference, and out-of-plane buckling. Especially, we find that spin-polarization in the GB correlates with out-of-plane buckling. We further investigate the characteristics of these classes in simulated scanning tunnelling spectroscopy and diffusive transport along the GB which demonstrate how current can be guided along the GB.
title First Principles Study of Electronic Structure and Transport in Graphene Grain Boundaries
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2401.06556