Conductivity engineering of graphene by defect formation

TL;DR

This study demonstrates that introducing vacancy defects in graphene unexpectedly increases its conductivity significantly, due to defect-induced mid-gap states that create metallic regions, with both theoretical and experimental validation.

Contribution

The paper reveals that vacancy defects can enhance graphene's conductivity, challenging previous expectations and providing a new method for electronic property control.

Findings

Conductivity increases with vacancy defect concentration.

Defect-induced mid-gap states create metallic regions.

Experimental and theoretical results are in agreement.

Abstract

Transport measurements have revealed several exotic electronic properties of graphene. The possibility to influence the electronic structure and hence control the conductivity by adsorption or doping with adatoms is crucial in view of electronics applications. Here, we show that in contrast to expectation, the conductivity of graphene increases with increasing concentration of vacancy defects, by more than one order of magnitude. We obtain a pronounced enhancement of the conductivity after insertion of defects by both quantum mechanical transport calculations as well as experimental studies of carbon nano-sheets. Our finding is attributed to the defect induced mid-gap states, which create a region exhibiting metallic behavior around the vacancy defects. The modification of the conductivity of graphene by the implementation of stable defects is crucial for the creation of electronic junctions in graphene-based electronics devices.