Structural, electrical, phonon, and optical properties of 2D metals: A DFT calculation

Abstract

We investigated the structure, electrical, phonon, and optical properties of 2D metals (goldene, silverene, and copperene) by density functional theory. The results of the electronic band structure reveal that goldene and copperene exhibit metallic characteristics, whereas silverene demonstrates semimetallic properties. The results of the electronic density of states show that the s–d-orbital coupling is the strongest in goldene, followed by silverene, and the weakest in copperene. The s–d-orbital coupling has the effect of softening phonons and reducing lattice thermal conductivity. Phonon property analysis demonstrates that there are no imaginary frequencies in the phonon dispersion curves of goldene, silverene, and copperene, indicating their dynamic stability. The results of optical properties show that goldene and copperene exhibit high absorptivity, reflectivity, conductivity, and refractive index in the low-frequency region, and the optical properties of the three 2D metals gradually converge to the same as the frequency increases. This research provides a theoretical foundation and guidance for exploring novel two-dimensional metal materials.