The effects of a Stone–Wales defect on the performance of a graphene-nanoribbon-based Schottky diode

Abstract

The effects of a Stone–Wales defect on the performance of a graphene-nanoribbon-based Schottky diode are studied herein. To this end, the transmission, energy band structure, density of states, carrier concentration, and current density of the proposed device are modeled analytically in two cases, viz. a pristine and defective graphene nanoribbon, and the results are compared. The results reveal that the introduction of a Stone–Wales defect into the symmetric graphene nanoribbon system obviously changes some of the distinctive properties. After the introduction of a Stone–Wales defect, the slope of the energy levels in the graphene nanoribbon is reduced, leading to a decrease in the Fermi velocity. In this case, the band gap near the Dirac points in the energy band structure is increased. The minimum density of states of the defect-free graphene is almost zero, which can be explained by the shape of the energy band diagram at the Dirac point. Moreover, the minimum density of states in the presence of a Stone–Wales defect is higher than in the defect-free condition, owing to the presence of bands throughout the energy diagram. Finally, the effects of the temperature and channel width on the I–V characteristic of the proposed Schottky diode based on a defect-free or defective graphene nanoribbon are studied analytically, and the efficiency of the device is investigated.