Size effect of V-shaped notches on the electronic transport properties of zigzag graphene nanoribbons

The electronic transport properties of zigzag nanoribbons (ZGNRs) with V-shaped notches on the edges have been investigated by a first-principles method. It is found that for ZGNRs with medium and large-sized V-shaped notches, an obvious threshold of the bias voltage can be observed in the I-V curve, which does not appear in pristine ZGNRs and small-sized V-shaped ZGNRs. Therefore, a method to convert ZGNR to semiconductor with considerable energy gap is suggested by introducing V-shaped notches with appropriate size on the edges. Moreover, the electronic conductivity of ZGNRs with medium-sized V-shaped notches is found to be superior to pristine, small and large-sized V-shaped-notched ZGNRs under high bias voltages. The difference in the electronic transport of these four systems is analyzed in terms of projected density of states and MPSH eigenstates.