Bright upconversion luminescence and increased Tc in CaBi2Ta2O9:Er high temperature piezoelectric ceramics

Abstract

Er3+ doped CaBi2Ta2O9 (CBT) bismuth layered-structure high temperature piezoelectric ceramics were synthesized by the traditional solid state method. The upconversion (UC) emission properties of Er3+ doped CBT ceramics were investigated as a function of Er3+ concentration and incident pump power. A bright green upconverted emission was obtained under excitation 980 nm at room temperature. The observed strong green and weak red emission bands corresponded to the transitions from 4S3/2 and 4F9/2 to 4I15/2, respectively. The dependence of UC emission intensity on pumping power indicated that a three-photon process was involved in UC emissions. Studies of dielectric with temperature have also been carried out. Introduction of Er increased the Curie temperature of CBT, thus, making this ceramic suitable for sensor applications at higher temperatures. Because of its strong up-converted emission and increased Tc, the multifunctional high temperature piezoelectric ceramic may be useful in high temperature sensor, fluorescence thermometry, and optical-electro integration applications.