Regulation Mechanism of Eu³⁺ Doping on the Luminescent Properties of Tb-ZrSiO₄ Yellow Fluorescent Pigments: A...

In response to the urgent demand for stable fluorescent materials in the field of high-temperature ceramic anticounterfeiting, this study proposes a novel design concept for dual-mode anticounterfeiting pigments based on Tb⁴⁺/Eu³⁺ codoped ZrSiO₄ (tetragonal crystal system, I4₁/amd space group) and systematically investigates the doping mechanisms and performance regulation patterns through first-principles calculations. The results show that Tb⁴⁺/Eu³⁺ can achieve stable doping in ZrSiO₄ through a cationic charge compensation mechanism, resulting in lattice expansion and charge redistribution. Electronic structure analysis shows that Tb⁴⁺ doping reduces the bandgap from 5.56 to 3.15 eV, forming an O_2p → Tb_4f charge transfer band, which gives the material yellow color characteristics. Tb⁴⁺/Eu³⁺ codoping further narrows the bandgap to 2.64 eV and may activate red-light emission through an energy transfer channel of Tb⁴⁺ → Eu³⁺. Electron localization function and differential charge density analyses reveal the chemical bond evolution and charge transfer characteristics of the doped system. The optical absorption spectrum confirms that the material has the ability for ultraviolet broadband absorption and characteristic excitation in the visible region, achieving a dual-mode response of "yellow light background-red light emission". This work elucidates the structure-activity relationship of the Tb⁴⁺/Eu³⁺ codoped ZrSiO₄ system at atomic scale and provides a theoretical basis for developing high-temperature stable fluorescent anticounterfeiting materials.