Tetrapyrroles-decorated graphene nanoribbons: Toward to the half-metal and ferromagnetic semiconductor

Abstract

Realization of the half-metallicity in graphene is of crucial importance in all-carbon organic spintronic nanodevices. Here, using first-principles calculations, we predicted the existence of half-metallicity in porphin-decorated graphene nanoribbons based on the synthesized porphin-decorated graphene [He et al., Nat. Chem. 9, 33–38 (2017)]. The configurations are constructed by coupling porphin molecules to one side of three different graphene nanoribbons: zigzag, sawtooth, and armchair graphene nanoribbons. We found that the porphin-decorated zigzag graphene nanoribbons (ZGNRs) exhibit half-metallicity, where their bandgaps are fixed at ∼0.3 eV for the gapped spin channel regardless of the variation of the ribbon width. Different from ZGNR, porphin-decorated sawtooth graphene nanoribbons exhibit ferromagnetic semiconducting properties, and for the armchair graphene nanoribbons, porphin modification only influences their bandgaps. Our findings open an avenue to the graphene-based electronic and spintronic devices.