▎ 摘　　要

The electronic structure and quantum transport properties of pristine armchair graphene nanoribbons (AGNRs) and AGNRs adsorbing super-halogen LiF2 and super-alkaline Li-3 clusters (Li-3/AGNRs/LiF2) were investigated using density functional theory and non-equilibrium Green's function calculations. It was found that LiF2 and Li-3 clusters are stably adsorbed on the AGNRs, and the adsorption of Li-3 and LiF2 endows AGNRs with the characteristics of n-type and p-type semiconductors, respectively. The Li-3/AGNRs/LiF2 structure reduces the band gap and the turn-on voltage, and improves the transmission coefficient of the ANGRs device. This structure also exhibit the rectification characteristics of a pn junction with the forward bias current greater than the reverse bias current. This shows that adsorption of super-alkali and super-halogen clusters in different regions of AGNRs is a feasible approach for obtaining AGNRs with pn junction characteristics. (C) 2020 Elsevier B.V. All rights reserved.