Electronic and optical properties of C60 under the influence of alkali metal injection: A DFT study

Abstract

This investigation explores the electronic structures and optical properties of pristine fullerene (C₆₀) and alkali metal-intercalated C₆₀ compounds (X@C₆₀; X = Li, Na, K, Rb, and Cs) using first-principles Density Functional Theory (DFT) calculations. The study is motivated by the growing interest in nanocarbon materials for next-generation optoelectronic devices. We employed the CASTEP code to optimize geometries and calculate electronic and optical properties of C₆₀ and X@C₆₀ structures. The Heyd − Scuseria − Ernzerhof functional (HSE06) was utilized for all computations. Our results demonstrate that the incorporation of a single alkali metal atom into the C₆₀ cage significantly modifies its electronic and optical characteristics. Specifically, we observed alterations in bandgap energy, total density of states (TDOS), absorption coefficient, dielectric function, refractive index, optical conductivity, reflectivity, and loss function of the C₆₀ material post-intercalation. These findings suggest that alkali metal intercalation could serve as an effective strategy for tuning the electronic and optical properties of C₆₀. This approach may offer a novel method for tailoring fullerene-based materials for specific optoelectronic applications.