Device design based on the covalent homocoupling of porphine molecules*

Abstract
Porphine has a great potential application in molecular electronic devices. In this work, based on the density functional theory (DFT) and combining with nonequilibrium Green’s function (NEGF), we study the transport properties of the molecular devices constructed by the covalent homocoupling of porphine molecules conjunction with zigzag graphene nanoribbons electrodes. We find that different couple phases bring remarkable differences in the transport properties. Different coupling phases have different application prospects. We analyze and discuss the differences in transport properties through the molecular energy spectrum, electrostatic difference potential, local density of states (LDOS), and transmission pathway. The results are of great significance for the design of porphine molecular devices in the future.