Temperature/electric field induced photoluminescence-modulation effect in dysprosium-doped barium titanate ferroelectric ceramics

Lanthanide (Ln3+) based ferroelectric phosphors, with an integration of PL emission and ferroelectric effect, are unveiling an exciting realm of possibilities for multifunctional ferroelectric-optic materials. However, how the ferroelectric host enables the tuning on the PL emissions through modulating the local structure (e.g., lattice site, symmetry, strains etc.) of the Ln3+ activator is not established yet. In this work, a luminescent-ferroelectric material, i.e. Dy3+ doped BaTiO3 ceramic (Ba1–xDyxTiO3 (x = 0∼0.07), abbr: BTO:Dy3+), was explored to address the aforementioned issues. The BTO:Dy3+ ceramics were synthesized by a solid-state reaction method. The crystal structure, photoluminescence (PL) and electric properties (dielectric constant, ferroelectric hysteresis and piezoelectric hysteresis loop) were systematically investigated. The BTO:Dy3+ ceramics show two predominant emission peaks, corresponding to the blue magnetic dipole transition (477 nm, 4F7/2 → 6H15/2) and yellow electric dipole transition (573 nm, 4F7/2 → 6H13/2), the intensity ration of which can be modulated by the ferroelectric polarization that causes the slight lattice deformation. Such a polarization-emission modulation combining with the Dy3+ doping could accelerate the color change, from yellow to blue, which is characterized to detect the phase transition, with a method and mechanism were proposed, that is, the phase change is reflected by the PL characteristic peak intensity ratio. Therefore, the current results offer a convenient photoluminescence method for detecting the ferroelectric phase transition and a feasible approach to study the interaction between the photoluminescence and polarization in ferroelectric materials, for providing new insights for the development of multifunctional materials.