Improved piezoelectric property and bright upconversion luminescence in Er doped (Ba0.99Ca0.01)(Ti0.98Zr0.02)O3 ceramics

• Enhanced temperature stability was obtained in the range from 20 to 100 °C.
• TO–T shifted to low temperature while Tc shifted conversely with the increase of Er.
• Bright upconversion luminescence was obtained under excitation (980 nm).

Lead-free (Ba0.99Ca0.01)(Ti0.98Zr0.02)O3 (BCZT) + x mol% (x = 0–0.8) Erbium (Er) ceramics were prepared using the solid-state reaction technique. Dielectric, ferroelectric, piezoelectric and photoluminescence properties were systematically studied. Greatly enhanced temperature stabilities of the piezoelectric properties were obtained in the temperature range from 20 to 100 °C. Broad ferroelectric phase (orthorhombic–tetragonal) transition (TO–T) tuned by Er doping was deduced from the dielectric properties. With the increase of Er content, the TO–T shifted towards low temperature, while Curie temperature (TC) shifted towards high temperature. Furthermore, bright green (525 and 550 nm) and weak red (670 nm) emission bands were obtained under excitation (980 nm) at room temperature, corresponding to the transitions of 2H11/2/4S3/2 → 4I15/2 and 4F9/2 → 4I15/2, respectively. As multifunctional material, Er-doped BCZT ceramics show great potential in mechano-electro-optic integration and coupling device applications.