Enhancement of field-induced strain and bright upconversion luminescence in BNT-based multifunctional ceramics

In this work, a multifunctional lead-free (Bi0.5Na0.5)0.945Ba0.065Ti(1−x)(Fe0.5Sb0.5)xO3-0.005Er (BNBT-Er-xFS) ferroelectric material was prepared through the solid-state method, which has a large reversible field-induced strain of 0.465% (under an moderate electric field of 65 kV/cm) with a high normalized strain d33* (Smax/Emax) of 713 pm/V. Besides the excellent strain properties, this system also exhibits a bright green upconversion emission under excitation of 980 nm due to the luminescence characteristic of Er3+ ion. Moreover, the upconversion luminescence performance of BNBT-Er-xFS is enhanced with the (Fe0.5Sb0.5)4+ doping. At x = 0.0075, sample exhibited the strongest upconversion luminescence. As a multifunctional material, the BNBT-Er-xFS system is expected to be used in multifunctional electronic devices due to its excellent electrical and photoluminescence performance.