Photoluminescence Properties of Er/Pr‐Doped K 0.5 Na 0.5 NbO 3 Ferroelectric Ceramics

Er/Pr‐doped K 0.5 Na 0.5 NbO 3 ceramics have been fabricated and the effects of Pr 3+ on their photoluminescence properties have been investigated systematically. The visible upconversion emissions, near‐infrared and mid‐infrared downconversion emissions of Er 3+ ions under the excitation of 980 nm have been studied in detail. The effects of Pr 3+ on PL properties and energy‐transfer processes have also been elucidated. By selecting an appropriate excitation source, simultaneous visible downconversion emissions of Er 3+ and Pr 3+ ions can be realized, and the emission colors of the ceramics can be tuned via the concentration of Pr 3+ ions in a wide range from yellowish green to yellow. Our results also reveal that the photoluminescence emissions of the ceramics can be enhanced by the alignment of polarization of the ferroelectric host.