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

•We study the tuning effects of carbon dopants on the electronic structures and magnetic properties of zigzag boron nitride nanoribbons.•The electronic structures and magnetism can be greatly altered by changing the dopant positions and concentration.•With careful control of the carbon dopant distributions, half-metallic zigzag boron nitride nanoribbons can be achieved.

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.