Lithium metasilicate and lithium disilicate nanomaterials: optical properties and density functional theory calculations

UV--vis and photoluminescence spectra of the hydrothermally synthesized crystalline lithium metasilicate (Li2SiO3) and lithium disilicate (Li2Si2O5) nanomaterials are studied. The intensity of the bands in the emission spectra increases with increasing reaction time in both compounds. The electronic band structure along with density of states calculated by the density functional theory (DFT) method indicates that Li2SiO3 and Li2Si2O5 have an indirect energy band gap of 4.575 and 4.776 eV respectively. The optical properties, including the dielectric, absorption, reflectivity, and energy loss spectra of the compounds, are calculated by DFT method and analyzed based on the electronic structures.