Crystallization and concentration modulated tunable upconversion luminescence of Er3+ doped PZT nanofibers

Abstract

Ferroelectric oxides with excellent electrical, mechanical and optical multifunctions play a vital role in future microdevices with diverse applications in energy, sensors and actuators. A series of Er doped PbZr_0.52Ti_0.48O₃ (PZT:Er³⁺) nanofibers with tunable upconversion photoluminescence (PL) properties were successfully synthesized via a sol–gel based electrospinning process. By controlled crystallization, PZT:Er³⁺ nanofibers evolve from a polycrystalline to a single-crystalline-like structure, resulting in a remarkable increase in the visible upconversion emission intensity. It was uncovered that Er³⁺ doping site in PZT shifts from B site to A site with increase in crystallinity and crystal size. In addition, remarkable enhancement in red emission is observed with increased Er³⁺ doping concentration, which facilitates the modulation of emission colour from green to orange. Combined with the excellent ferroelectric properties of PZT, such spectral tunable PZT:Er³⁺ nanofibers are considered as a promising multifunctional candidate for integrated electro-mechano-optical devices.