▎ 摘　　要

In this work, we investigated the effect of B, P, As and Sb on the electronic and transport properties of 7-armchair graphene nanoribbons (7-AGNRs) nanoscale p-n junctions, where 7 was the width of nanoribbons. The first-principles study has been employed in the present analysis to reveal that selected dopants significantly reduced the band gap of pristine 7-AGNRs. The current voltage (I-V) curves of doped devices showed a robust inverse rectification direction, i.e., positive cut-off and reverse conduction, and the rectifying ratio (RR), which can reach up to 10(7). This was because the asymmetric electron accumulation phenomenon after doping led to the carriers in the device appearing an unbalanced effect under the action of the potential barrier, thereby resulting in a large reverse rectification effect. Simultaneously, these molecular devices possessed a reverse-bias current that increased almost linearly, a very low threshold voltage, and a negligible low forward leakage current that was not over 6.5 mu A. An obvious negative differential resistance (NDR) effect was also occurred in B/P co-doped molecular device with a peak-to-valley ratio of 2.3 x 10(5). In addition, under the same doping position, by varying the width of AGNRs, the results showed that the rectification effect varied with the width of the nanoribbons.