Current Characteristics of Defective GNR Nanoelectronic Devices

The most promising Graphene structures for the development of nanoelectronics and sensor applications are Graphene nanoribbons (GNRs). GNRs with perfect lattices have been extensively investigated in the research literature; however, fabricated GNRs may still suffering from lattice flaws, the possible effect of which, on the operation of the circuitry comprised by GNR based devices, has not attracted significant interest. In this paper, we investigate the effect of lattice defects on the operational behavior of GNRs using the Non-Equilibrium Green's function (NEGF) method combined with tight-binding Hamiltonians targeting to the resulting nanoelectronic devices and circuits functionalities. We focus on butterfly-shaped GNRs, which have been proven to successfully function as switches that can be used as building blocks for simple Boolean gates and logic circuits. Analyses of the most common defects, namely the single and double vacancies, have been adequately performed. The effect of these vacancies was investigated by inserting them in various places and concentrations on the corresponding GNR based nano-devices. The computation results indicate the effect on lattice defects on the important operational device parameters including the leakage current, ION/IOFF and, finally, current density, which will determine the viability of GNR computing circuits.