Influence of edge termination on the electronic and transport properties of sawtooth penta-graphene nanoribbons

Abstract

The electronic and transport properties of sawtooth penta-graphene nanoribbons (SSPGNRs) are investigated using density functional theory and semi-empirical extended Hückel method in combination with nonequilibrium Green functions. The configurations are theoretically studied in terms of bare edges (Bare-SSPGNR) and edges terminated by non-metallic atoms (H, P, Si) such as: identical edge termination (HH-SSPGNR, PP-SSPGNR and SiSi-SSPGNR) and alternate edge termination (PH-SSPGNR and SiH-SSPGNR). It is found that SSPGNR band gap can be controlled through changing various passivation elements as well as termination forms, which leads to the transition from a semiconductor to a metal or a semimetal. For the influence on transport properties, P and Si atoms of alternate cases improve significantly the weak point (very poor current) of the bare and traditionally passivated models. The 9-order rise of current magnitude is observed in PH-SSPGNR and SiH-SSPGNR compared to HH-SSPGNR and PP-SSPGNR. Interestingly, oscillation current-voltage characteristic appears when SSPGNR is identically functionalized by Si atoms. These outcomes derive from the strong dependence of SSPGNRs on edge chemistry influence, suggesting that kinds of passivation atoms and termination types could be used to manipulate properties of novel and promising materials in nano-electronic devices.