Doping-induced bandgap tuning in armchair graphene nanoribbons and its impact on electron transport properties on ZAPn – A DFT study

Abstract

Graphene, sp2 hybridised-2D material has been widely reviewed for its fabulous structural, electronic, magnetic and optical properties. However, its employment in energy-related devices are controlled due to its semi-metallic nature. A quasi one-dimensional structure of graphene is called as graphene nanoribbon (GNR). Tuning the band gap of GNR based on its width can be achieved via doping. The present work envisages, the doping performance on the electronic properties of armchair graphene nanoribbon AGNR (N9) doped with Boron (B), Nitrogen (N) and Phosphorus (P) in a Z-shape. The effect of B, N, and P dopants in AGNR(N9) systems were analysed by varying the concentration from 0.75 % to 3.03 %. Our results predicts that the band gap has been reduced by the impact of dopants, and also ZAPn systems shows better results in lower concentration of dopants than ZABn and ZANn systems. Further, it is observed that, with the increase in the concentration of P dopants, their electronic structure is transformed from n-type to p-type. Transport calculations were performed for ZAPn systems, and their properties were analyzed with the help of transmission spectrum, device density of states (DDOS), and I-V characteristics. All the doped as well as the pristine two-probe device structures established non-linear current vs. voltage characteristics. The ZAP3 doped system achieved a maximum current of 60 µA. The present study will be established to construct AGNR(N9) based nano-electronic devices.