The electronic structures and optical properties of Zn2GeO4 with native defects

The electronic structures and optical properties of zinc germinate (Zn2GeO4) with native defects are investigated by density functional theory. Calculations reveal the existence of dipole moments which explains the photocatalytic activity. Defect energy level induced by oxygen vacancy along with the unfulfilled Zn 3d, are most responsible for luminescence. Formation energy reveals the abundance of vacancy and can support the experimental correlation of emission intensity with oxygen vacancy density. Optical indexes and absorption spectra are calculated by Kramers-Kronig relations. The calculations help understand better the nature of Zn2GeO4 that is beneficial for its various practical applications.