Surface decoration of phosphorene nanoribbons via 4d transition metal atoms for spintronics
Recent production of phosphorene nanoribbons provides a platform for designing phosphorene-based high-speed electronic devices. Introducing magnetic moment to phosphorene nanoribbons towards spintronics is attractive. Based on density functional theory combined with non-equilibrium Green’s function method, the electronic, magnetic and spin-polarized transport properties of phosphorene nanoribbons modified by adsorption and substitutional doping of 4d transition metal atoms (Y, Zr, Nb and Mo) are investigated systematically. The results show that both adsorption and doping of 4d transition metal atoms can import magnetic moment into phosphorene nanoribbons, except Y- and Nb-doping cases. The adsorption manner has superior performance in terms of modulating the electronic and magnetic properties of phosphorene nanoribbon than substitutional doping, exhibiting higher spin polarization near Fermi level with narrower band gap. This discrepancy originates from different electron redistribution in adsorption and doping situations. Furthermore, the nanoribbons adsorbed by transition metal atoms exhibit excellent spin-polarized transport properties: a giant magnetoresistance ratio of the Mo-adsorbed nanoribbon reach over 10^8 under low bias; the Y-Mo adsorbed nanoribbons with parallel spin configurations show about 100% spin filtering effect with bias larger than 0.1 V, and those with antiparallel spin configurations exhibit a dual spin filtering effect in applied bias range of (-0.2 V, 0.2 V). Our results demonstrate that 4d transition metal atoms adsorption is a favourable approach to modify the electronic, magnetic and transport properties of phosphorene nanoribbons, thus providing a reference for rational design of spintronic devices based on phosphorene nanoribbons.