Significant negative differential resistance and rectification effect induced by C₃Al nanoribbon edge morphology

Abstract The recently predicted two-dimensional material C 3 Al has a graphene-like lattice structure, but the presence of Al atoms leads to a variety of edge morphologies when it is one-dimensionally clipped. In this paper, the electron transport properties of C 3 Al nanoribbons are investigated by first-principles calculations. The results show that they are strongly edge-dependent, being a semiconductor when there are two Al terminal edges, otherwise behaving as metals. Based on this, C 3 Al heterojunction devices with different edge morphologies are constructed, in which the 3CAl-NCC and 3CAl-NCAl devices show significant negative differential resistance effects with peak-to-valley ratios up to 2.3 × 10 4 , but such effects diminish with the widening of NCAl, mainly due to the increase of the interfacial spatial barriers suppressing the conductive channel generated by the edge state. The 3CAl-NCAl heterojunction also displays a remarkable rectification effect with a rectification ratio as high as about 1.6 × 10 3 . The rich electronic properties bode well for their promising applications in nanodevices.