Effect of side gates doping on graphene self-switching nano-diode rectification

Abstract

Based on the self-consistent charge density functional tight-binding method, the electrical properties and rectification behavior of graphene self-switching nanodiodes with B and N atoms doped side gates are investigated. The doping changes the electrical conductivity of the side gates and the semiconductor channel nanoribbons. From the band structure and Mulliken population analysis in the N-doped (B-doped) structures, we found that the N (B) energy levels are located above (below) the conduction band minimum (valence band maximum) and that these impurities are autoionized such that the excess electrons (holes) are transferred to the conduction (valence) band. In the doped devices, the threshold voltage under the forward bias is significantly reduced such that in the 565-B doped and 565-N doped devices, the threshold voltage is approximately zero. In addition, compared with the corresponding undoped devices, the electric current in doped devices under the forward and reverse biases is increased and decreased, respectively. Finally, among all of our structures, in the range of applied bias, the 565-B doped device exhibited the highest rectification ratio of 5.59 × 102, whereas the maximum current value of 12.7 μA under the forward bias conditions was obtained with the 666-B Doped GSSD structure.