Promising optical characteristics of zinc peroxide from first-principles investigation

The structural, electronic and optical properties of zinc peroxide have been investigated using first principle pseudopotential method within generalized gradient approximation (GGA) proposed by Perdew-Burke-Ernzerhof (PBE) and also within Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional for the exchange-correlation. An underestimated band gap (1.77 eV) along with the higher density of states and expanded energy bands around the Fermi level is obtained. The HSE06 approach corrects the band gap and allows a proper description of defects with energy levels close to the conduction band. According to the HSE06 calculations, the obtained band gap is 3.2 eV. This value is very close to semiconductors band gap such as TiO2 (3.1 eV). The dielectric constants are identified with respect to electronic band structure and are utilized to derive the other optical properties such as retractive index, energy loss function, reflectivity and absorption. This mainly shows that zinc peroxide is a poor absorber of visible light.