Effects of lithium intercalation on the electronic and optical properties of graphene: Density Functional Theory (DFT) computing

In this article, the electronic and optical characteristics of pristine graphene and intercalated with lithium ions $(\text{Li}^{+})$ are analyzed using computation based on Density Functional Theory (DFT). The CASTEP software is used to build and simulate the armchair graphene system. The presence of lithium ions has an effect on the bandgap energy, total density of states (TDOS) and optical properties of graphene, causing them to be altered. The bandgap energy is increased with lithium-intercalated graphene concentration. The effect of doping graphene wirh $\text{Li}^{+}$ leads to an increase in TDOS peaks at the Fermi level. The absorption of pristine graphene experiences a decrease in the ultraviolet (UV) spectrum and an increase in the visible range due to the process of $\text{Li}^{+}$ ions intercalation. Our finding suggest that the $\text{Li}^{+}$ ions modulates the armchair graphene’ s electronic and optical properties. The results of this research provide an approach to use the lithium ions to control the electronic and optical characteristics of a graphene layer. We can develop future experiments to analyze the properties of graphene material using this study as a theoretical basis.