High rectifying performance of heterojunctions with interface between armchair C$_3$N nanoribbons with and without edge H-passivation

Abstract

Two-dimensional polyaniline with C$_3$N stoichiometry, is a newly fabricated layered material that has been expected to possess fascinating electronic, thermal, mechanical and chemical properties. The nature of its counterpart nano-ribbons/structures offering even more tunability in property because of the unique quantum confinement and edge effect, however, has not been revealed sufficiently. Here, using the first-principles calculation based on density functional theory and nonequilibrium Green's function technique, we first perform a study on the electron band structure of armchair C$_3$N nanoribbons (AC$_3$NNRs) without and with H-passivation. The calculated results show that the pristine AC$_3$NNRs are metal, while the H-passivated ones are either direct or indirect band gap semiconductors depending on the detailed edge atomic configurations. Then we propose a lateral planar homogenous junction with an interface between the pristine and H-passivated AC$_3$NNRs, in which forms a Schottky-like barrier. Interestingly, our further transport calculation demonstrates that this AC$_3$NNRs-based heterojunction exhibits a good rectification behavior. In specification, the average rectification ratio (RR) can reach up to $10^3$ in the bias regime from 0.2 to 0.4 V. Particularly, extending the length of semiconductor part in the heterojunction leads to the decrease of the current through the junction, but the RR can be enlarged obviously. The average RR increases to the order of $10^4$ in the bias from 0.25 to 0.40 V, with the boosted maximum up to $10^5$ at 0.35 V. The findings of this work may be serviceable for the design of functional nanodevices based on AC$_3$NNRs in the future.