ENGINEERING THE ELECTRONIC PROPERETIES OF ARMCHAIR GRAPHENE NANORIBBONS VIA Mn/Cr TERMINATION

Abstract

The structural and electronics properties of Mn and Cr- terminated armchair graphene nanoribbons (AGNRs) in our present paper employing ab-initio approach based on Density Functional Theory. Maintaining self-consistency throughout the simulations, we used Local Density approximation (LDA) as proposed by Perdew and Zunger to account for the exchange and correlation energy term. Stability analysis has been done by calculating the binding energy per atom of each configuration, while electronic properties are deduced from the study of band structures and density of states. Binding energy calculations suggest that one edge Mn terminations are energetically more favorable than double edge termination. Our simulation results show that the addition of Mn and Cr impurities at the edges of AGNRs greatly enhances the stability and lowers the band gap in general .Interestingly strong hybridization is the reason due to which direct band gap of H-terminated AGNR is changed into the indirect band gag in most of the configurations. Our calculation further strengthen the argument that the transition metal as a impurity in the AGNRs can play an important role in the band gap engineering of nano ribbons for future application in the nano-semiconductor devices.