A DFT Investigation of the Electronic and Optical Properties of Pentadiamond
Abstract
Recently, a new carbon 3D carbon allotrope named pentadiamond was proposed. Pentadiamond is composed of carbon atoms in mixed sp2 and sp3-like hybridization. In this work, we have carried out a detailed investigation of the electronic and optical properties of pentadiamond structure using first-principles (DFT) methods. Our results show that pentadiamond has an indirect bandgap semiconductor of 2.50 eV with GGA-PBE and 3.31 eV with HSE06. Its static dielectric constant is 4.70 and the static refractive index is 2.16. Pentadiamond presents low reflectivity, almost 40\%, for all-optical spectrum, making it a good structure to be used as a UV collector. Also, pentadiamond exhibits optical activity in the UV range where other carbon allotropes, such as diamond and 8-tetra(2,2) tubulane show no activity.