▎ 摘　　要

Hexagonal boron nitride sheet has been shown to be the best insulating substrate for graphene electronics. Using first-principles calculations, we here show that BN nanoribbons (BNNRs) can not only serve as a desirable substrate but also bring new properties into the supported graphene nanoribbons (GNRs). In particular, zigzag GNRs on zigzag BNNRs become a spin-relevant semiconductor that can be easily tuned into a half-metal, thanks to polar character of the BNNRs. In contrast, armchair GNRs can basically have all their electronic properties survived from the interaction of armchair BNNRs. Our findings provide helpful guide for developing hybrid BN-graphene nanodevices. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4798593]