Polarization Induced Switching Effect in Graphene Nanoribbon Edge-Defect Junction

TL;DR

This study uses ab initio calculations to explore how polarization effects influence electron transport in graphene nanoribbon junctions, revealing defect-sensitive tunneling control via electric fields.

Contribution

It introduces a combined NEGF-DFT approach with tight-binding validation to analyze polarization-induced switching in edge-defect graphene nanoribbons.

Findings

Tunable tunneling current controlled by transverse electric fields.

Abnormal transmission spectrum features explained by band structure.

Validation of tight-binding approximation against ab initio calculations.

Abstract

With nonequilibrium Green's function approach combined with density functional theory, we perform an ab initio calculation to investigate transport properties of graphene nanoribbon junctions self-consistently. Tight-binding approximation is applied to model the zigzag graphene nanoribbon (ZGNR) electrodes, and its validity is confirmed by comparison with GAUSSIAN03 PBC calculation of the same system. The origin of abnormal jump points usually appearing in the transmission spectrum is explained with the detailed tight-binding ZGNR band structure. Transport property of an edge defect ZGNR junction is investigated, and the tunable tunneling current can be sensitively controlled by transverse electric fields.