Strain engineering of chevron graphene nanoribbons

摘要： In this work, we theoretically investigate the material and transport properties of strained chevron graphene nanoribbons (CGNRs) which can be easily synthesized by the bottom-up fabrication technology. Because of the unique atomic structures, the energy and pressure of the CGNRs vary asymmetrically along compressive and tensile strains. Under the two strain directions, the CGNRs’ bandgaps and carrier effective masses in the conduction band minimum and the valence band maximum are all reduced. The transport properties are promoted accordingly, except some negative differential conductance behaviors caused by energy state localizations. When the tensile strains exceed a criterion value, the C–C bonds in the inner sides of the CGNR corners will be broken in sequence. Meanwhile, the CGNRs can restore their initial unstrained states rapidly when the strains are removed. However, if the broken bonds are saturated by foreign atoms, such as H, a novel kind of stable carbon structure will be obtained. The investigations suggest possible applications of strain engineered CGNRs in transport devices.