Electronic properties of a dual-gated GNR-FET under uniaxial tensile strain

We report the results of simulating a dual-gated grapheme nanoribbon field-effect transistor (GNR-FET) working in the ballistic regime, when its channel is under various tensile uniaxial strain. Simulations are performed based on self consistent solutions of the Poisson equation coupled with the Non-Equilibrium Green’s Function (NEGF) formalism in mode space representation, assuming a tight-binding Hamiltonian. The results show that the transistor I–V characteristics exhibit a zigzag behavior as the strain increases from ε = 0% to ε = 10.17%, at which the GNR bandgap equals that of the unstrained one. The simulations also reveal that initially the current decreases while the strain increases to ε = 5%. However, as the strain increases further, the current also increases, albeit at a rate that is less than that of the initial decrease. This behavior is consistent with the variations of GNR band gap under strain. Furthermore, other switching characteristics such as transconductance, DIBL and Ion/Ioff are also studied, for which similar zigzag behaviors are observed.

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