Electronic structures and transport properties of armchair graphene nanoribbons by ordered doping

Based on the first-principles method, the electronic structures and transport properties of armchair graphene nanoribbons (AGNRs) with ordered doping of B atoms or N atoms or BN molecules are studied systematically. It shows that the AGNRs may be a metal or a semiconductor depending on B or N atom-doping positions, and the calculated atom-projected density of states (atom-PDOS) indicates that B or N impurity atoms can induce the new lowest conduction band (LCB) or the highest valence band (HVB). More interestingly, as compared with the intrinsic AGNR device, the current in the B- or N-doped AGNR device with the most energetically favorable state is extremely small, completely different from a macroscopic Si semiconductor with p-type or n-type doping, which always leads to a significant increase in current. Also shown is that the doping with BN molecules generally increases the bandgap of the AGNR regardless of the doping position, but the size of these bandgaps depends on the doping positions. The current in the BN-doped AGNR device is also decreased greatly in comparison with that for the intrinsic AGNR device. (C) 2015 Elsevier B.V. All rights reserved.