▎ 摘　　要

By using the non-equilibrium Green's function formalism combined with density-functional theory, we present a theoretical study of the spin-dependent electron transport of a molecular device constructed from a chromium porphyrin molecule linking with two carbon chains sandwiched between two semi-infinite zigzag-edged graphene nanoribbon (ZGNR) electrodes, where the ZGNRs are modulated by an external magnetic field. The results show that the single spin-conducting can be obtained by performing different magnetic configuration of the leads. The coexistence of spin-filtering with 100% spin-polarization, rectifying and negative differential resistance (NDR) behaviors in our model device is demonstrated and mechanisms are proposed for these phenomena.