The photoluminescence and electrical properties of lead-free (Bi0.5Na0.5)TiO3:Pr ceramics

Pr doped lead-free (Bi0.5Na0.5)TiO3(BNT) ceramics were fabricated using the solid-state reaction method. The dependences of photoluminescence properties on process conditions, dopant concentration, and charge compensation were systematically investigated. The results showed that Pr-doped BNT ceramics exhibited strong red emitting properties with a single peak centered at 610 nm upon blue light excitation (440-505 nm), while maintaining high piezoelectric properties. The emission intensities reached the optimal value as the holding time is 2 h at 1150 °C for BNT:0.003Pr sample. Especially, the red emission intensity of BNT:xPr3+ can be more effectively enhanced by introducing the (Bi0.5Na0.5)2+ vacancies as the charge compensation due to the formation of trapping centers, than the alkali metal ions (Li+, Na+, K+) as compensators. In addition to the intrinsic piezoelectric properties, the excitation band of BNT:xPr material can well realize the compatibility with existing blue light-emitting diode chips (450-470 nm), compared to the ultraviolet or infrared light excitation luminescent materials, indicating that this system may have significant technological promise in novel multifunctional devices.