Abstract: By using combination of  nonequilibrium Green’s function (NEGF) and density functional theory (DFT),  the spin transport properties of four molecular junctions (M1—M4) consisting of rhenium azulenocyanine isomers (m1—m4) bridged to zigzag graphene nanoribbon (ZGNR) electrodes were investigated. The research results show that the transport properties of different isomers vary significantly. Among them,  the device M1 constructed based on the m1 molecule has the best overall performance:  In the parallel (P) ferromagnetic electrode configuration,  the spin filtration efficiency (η_SFE) is consistently higher than 98% under bias voltages ranging from 0 to 0.6 V;  a significant negative differential resistance (NDR) effect is observed in the bias voltage interval from 0.4 V to 0.55 V;  and the magnetoresistance ratio (R_MR) is as high as 4  493% at a specific bias voltage of 0.20 V. It can be seen that the rhenium azulenocyanine/ZGNR molecular junctions can effectively integrate high η_SFE,  ultrahigh R_MR,  and significant NDR effects into a single junction,  which provides a theoretical foundation for designing novel multifunctional molecular spintronic devices.

Key words: rhenium azulenocyanine,  , isomers,  , spin transport,  , spin filtration effect,  , magnetoresistance effect,  , negative differential resistance effect