Ferroelectric surface induced electron doping in zigzag graphene nanoribbon

The interface between a zigzag graphene nanoribbon (zGNR) and the ferroelectric PbTiO3 (001) surface is studied through first-principles calculations. We investigate how the electric polarization normal to the surface tunes the zGNR electronic and magnetic properties. A ferroelectric single-domain configuration with polarization up and down is considered including explicitly a bottom metallic electrode. Our results show how not only the ferroelectric polarization direction determines the doping in zGNR-the downward polarization induces a p-type doping in a planar zGNR whereas the upward polarization keeps it intrinsic- but also the features of the clean ferroelectric surface, such as the atomic relaxation and the electronic distribution. Interestingly, the surface ferroelectric polarization, besides tuning the carrier type as it does in graphene, also closes the zGNR band gap which can be understood in terms of the weakening of the local magnetic moment of the edge carbon atoms as the polarization increases. The zGNR antiferromagnetic ground state is preserved without breaking the α-β degeneracy.Fil: Belletti, Gustavo Daniel. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Programa de Electroquímica Aplicada e Ingeniería Electroquímica; ArgentinaFil: Dalosto, Sergio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Tinte, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentin