Effect of Single Vacancy Defect on ION/IOFF and Subthreshold Swing in Electrostatically Doped Armchair Graphene Nanoribbon Field-effect Transistor with Different Widths

Graphene has sparked a lot of interest due to its unique physical and electrical properties and emerged as a possible silicon replacement in FET technology. In this paper, the transfer and output characteristics of an electrostatically doped (ED) 7 Armchair Graphene Nanoribbon 10 nm (channel) FET (AGNR- FET) and the transfer characteristics of different (3m & 3m+1 where m is a positive integer) AGNR-FETs (10 nm channel) with three gates are investigated. The atomic interaction between carbon atoms is described by the tight-binding model with the nearest-neighbor approximation. The Poisson and Schrodinger equations are self-consistently solved within the non-equilibrium Green’s function (NEGF) formalism to simulate the characteristics of the transistors. Results show that a single vacancy (SV) defect at the center of the channel region significantly increases the I
ON
/I
OFF
ratio and decreases the subthreshold swing for both 3m & (3m+1) AGNR-FET. For every value of m, the (3m+1) AGNR-FET provides a higher I
ON
/I
OFF
ratio and lower subthreshold swing than 3m AGNR-FET for both cases with or without defect.