First-principles investigation of electronic and optical properties of COF-LZU1: A two-dimensional covalent organic framework

In this research, electro-optical characteristics of a covalent organic framework named COF-LZU1 are examined by density functional theory. The results demonstrate that COF-LZU1 sheet is structurally stable, as indicated by its negative cohesive energy and ab initio molecular dynamics simulations. The electronic property analysis reveals the semiconducting behavior of COF-LZU1. The study further explores the optical characteristics of COF-LZU1, including the dielectric function, optical conductivity, absorption coefficient, reflection, and transmission coefficients across a broad range of photon energies. Owing to its atomic structure, COF-LZU1 displays pronounced in-plane and out-of-plane optical anisotropy. The findings indicate that the dielectric constant of COF-LZU1 is comparable to that of other highly porous sheets, such as graphdiyne. The incident light is effectively absorbed in the visible and ultraviolet regions. The material is transparent due to its low reflection coefficient and high transmission coefficient. Collectively, these optical properties suggest that COF-LZU1 has promising potential for use in optoelectronic devices, operating in the visible and ultraviolet regimes.