Edge morphology induced rectifier diode effect in C3N nanoribbon

Abstract

The two-dimensional material C₃N has a honeycomb structure similar to graphene, but its heterogeneity of carbon and nitrogen elements makes it multifunctional. By performing a first-principles study, we find that edge morphology induces interesting electronic transport properties in step-like heterojunction devices composed of width-variable zigzag C₃N nanoribbons. As long as the right part has an edge of all-carbon morphology, negative differential resistance and rectification effects will occur. If both edges are not of all-carbon morphology due to the presence of N atoms, a forward-conducting and reverse-blocking rectifier diode behavior will appear. These phenomena originate from the peculiar electronic structure of the zigzag C₃N nanoribbons. The number of energy bands crossing the Fermi level gradually decreases from 2 to 0 as the number of all-carbon edges decreases, realizing a transition from metal to semiconductor. The band gap determines the cut-off region at low bias and the presence of an interface barrier causes the cut-off state to continue under high reverse bias. Diverse edge morphologies, simple cutting methods and rich electronic transport properties make C₃N materials competitive in nanodevice applications.