Tuning the electronic and magnetic properties in zigzag boron nitride nanoribbons with carbon dopants

We report a first-principles investigation on the tuning effects of carbon dopants on the electronic structures and magnetic properties of zigzag boron nitride nanoribbons (ZBNNRs). In particular, 10-ZBNNR is considered and a supercell with five unit cells is adopted in the calculations. When the supercell is doped by one carbon (C) atom, the dopant tends to substitute the edge atom resulting in a 0.625μB magnetic moment on the dopant and the system becomes a magnetic semiconductor. By changing the dopant position, namely, from the edge to the ribbon center, the nanoribbon transforms from a magnetic semiconductor into a metal. If the edges of the supercell are doped by two C atoms, the nanoribbons become a nonmagnetic semiconductor. With the increase of the dopant concentration, the conductivity of the ZBNNRs can be greatly improved. Especially, with careful design of the dopant distribution, half-metallic ZBNNRs can be achieved.