Study on the optical properties of Sm³⁺ doped bismuth silicate crystals based on first principles

Abstract This study systematically investigated the effect of Sm 3+ doping on the optical properties of bismuth silicate (Bi 4 Si 3 O 12 , abbreviated as BSO) crystals using first principles calculations based on density functional theory (DFT). By calculating the dielectric function, reflectivity, absorption coefficient, refractive index, conductivity, and energy loss function of BSO crystals under different Sm 3+ doping ratios, we found that moderate Sm 3+ doping can increase the dielectric function of BSO crystals, and the real part of the dielectric function represents the material’s ability to respond to the electric field, that is, the macroscopic polarization degree. Therefore, moderate Sm 3+ doping enhances the polarization ability of BSO crystals. Simultaneously doping an appropriate amount can effectively enhance the conductivity and light (visible and infrared) absorption ability of BSO crystals, and reduce the energy loss between electrons in BSO crystals, thereby improving their luminescence performance. Specifically, when the Sm 3+ doping ratio is 1/6, the optical properties of BSO crystals are significantly improved. These findings not only enhance the understanding of the mechanism of optical performance changes in rare earth ion doped BSO crystals, but also provide a theoretical basis for the development of new rare earth doped optical materials.