▎ 摘　　要

The graphene nanoribbon (GNR) field effect transistor is one of the most competitive candidates for beyond-CMOS nanoelectronics because of the special electric characteristics of graphene. During graphene preparation, vacancy defects are inevitably introduced and affect transistor performances. In this Letter, four typical vacancy defects in GNR (i.e. single vacancy, divacancy, Stone-Wales and 555 777 defects) are examined. By quantum-mechanics-based simulation, the effects of these four defects on the energy band of the GNR are analysed. Moreover, their effects on the performances of the GNR field effect transistor, such as transmission coefficient and transfer characteristics, are studied and compared for various defect locations in the channel.