Enhanced Photoluminescence in Pr-Doped (Bi_0.5Na_0.5)TiO₃-BaTiO₃ Ceramics Induced by Electric Field Poling

Herein, we report significantly enhanced photoluminescence in Pr-doped (Bi_0.5Na_0.5)TiO₃-BaTiO₃ ceramics induced by electric field poling. The photoluminescence (PL) intensity enhancement rates (Δ_PL) initially increased and subsequently decreased with increasing the poling electric field, reaching maximum values of 47.95% and 36.05% for 0.93(Bi_0.5Na_0.5)_0.996TiO₃-0.07BaTiO₃-0.004Pr (BNBT-0.004Pr) and 0.93(Bi_0.5Na_0.5)_0.988TiO₃-0.07BaTiO₃-0.012Pr (BNBT-0.012Pr) ceramics after poling under electric fields of 30 and 40 kV/cm, respectively. The observed Δ_PL enhancement was attributed to structural inhomogeneity arising from the formation of the P4mm phase and the tetragonal-to-rhombohedral phase transition. Further increases in the poling electric field resulted in a decrease in Δ_PL intensity, which was attributed to non-180° domain switching and the disappearance of heterojunctions induced by the higher poling electric field. Additionally, an excellent piezoelectric constant of 189 pC/N was achieved in the BNBT-0.004Pr ceramic. This study provides a comprehensive theoretical and experimental framework for the development and practical application of optoelectronic devices, highlighting the significant potential for advancing multifunctional materials and integrated device systems.