Modeling comparison of graphene nanoribbon field effect transistors with single vacancy defect

• A graphene nanoribbon field effect transistor (GNRFET) with n-type source and drain and intrinsic channel is studied.
• Real-space Non-Equilibrium Green Function (NEGF) formalism is used.
• The effect of single vacancy (SV) defect on transistor performance is examined.
• The 3SVsGNRFET has smaller capacitance in comparison with Ideal GNRFET.
• The 3SVsGNRFET has good Drain Induced Barrier Lowering (DIBL) and sub-thershold swing.

In this paper, some important circuit parameters of a monolayer armchair graphene nanoribbon (GNR) field effect transistor (GNRFET) in different structures are studied. Also, these structures are Ideal with no defect, 1SVGNRFET with one single vacancy defect, and 3SVsGNRFET with three SV defects. Moreover, the circuit parameters are extracted based on Semi Classical Top of Barrier Modeling (SCTOBM) method. The I-V characteristics simulations of Ideal GNRFET, 1SVGNRFET and 3SVsGNRFET are used for comparing with SCTOBM method. These simulations are solved with Poisson-Schrodinger equation self-consistently by using Non- Equilibrium Green Function (NEGF) and in the real space approach. The energy band structure of nanoribbon is obtained by using nearest–neighbour interactions within an approximation tight-binding method. The modeling results show that 3SVsGNRFET in comparison to 1SVGNRFET has higher transconductance, cut-off frequency, electron average velocity, mobile charge, and quantum capacitance. Also, 3SVsGNRFET has smaller gate, drain and source capacitances than Ideal GNRFET. Furthermore, Drain-induced barrier lowering (DIBL) and sub-threshold swing (SS) of 3SVsGNRFET are smaller than 1SVGNRFET.

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