Estudo das Modificações Eletrônicas e Estruturais em Heteroestruturas Grafeno-Bifenileno: Utilizando métodos de primeiros princípios DFT

Abstract

This dissertation presents a theoretical investigation of the electronic and structural proper- ties of graphene-biphenylene heterostructures, exploring modifications in various aspects, including hydrogenation, mechanical deformation and stacking with graphene sheets. Using first- principles methods based on Density Functional Theory (DFT), we examine the interaction between graphene and biphenylene, revealing charge transfer and modifications in band structures before and after hydrogenation. By applying mechanical deformations, we identified notable patterns in the bandgaps, indicating tunable control over electronic properties. Stacking with graphene sheets was investigated, highlighting stacking. The analysis revealed a reallocation of load in the structures, except for one specific case that showed a net transfer between the components. Furthermore, by applying external electric fields, we demonstrate control over charge transfer, promoting the creation of regions in the graphene sheet susceptible to donating or receiving charge, offering potential applications in electronic devices. These results provide an in-depth understanding of modifications in graphene-biphenylene heterostructures, highlighting the versatility of these materials and the ability to tune electronic properties through diverse strategies.