New monolayer penta-nanostructures: First-principles calculations

In this paper, the first principle study of the electronic and optical properties of new monolayer penta-(C4B2, C2B4, and C2N4) via the density functional theory (DFT) and using the Wien2k code are studied. Our results demonstrate that the monolayer penta-(C4B2, C2B4, and C2N4) are semiconductors with gap energies 0.2 eV, 1.2 eV, and 3.1 eV, respectively. Also, in the optical properties section, a number of optical parameters optical virtues such as reflectivity, dielectric function, and energy loss function versus energy variations are calculated. The results of the optical calculations show that, in the x-polarization of the electric field, the optical band gap corresponds to the electronic band gap, and the plasmon energy matches with the free electron model. Also, the effective number of electrons in an energy of about 15 eV was found to be equivalent to 21, 20, and 20 electrons, respectively, which is small compared to the free electron, due to the localization of the number of electrons.