Up-conversion luminescence of Er~(3+) and Yb~(3+) co-doped CaBi_2Ta_2O_9 multifunctional ferroelectrics

摘要

Er~(3+) and Yb~(3+) co-doped CaBi_2Ta_2O_9 (CBT)-based bismuth layered-structure oxides were synthesized by a simple solid-state reaction method. Their up-conversion (UC) luminescence, dielectric and ferroelectric properties were investigated. Two strong green emission bands centered at 526 and 547 nm and a weak red emission band centered at 658 nm were obtained under a 980 nm laser excitation at room temperature. These emission bands originated from the radiative relaxation of Er~(3+) from ~2H_(11/2), ~4S_(3/2), and ~4F_(9/2) levels to the ground state ~4I_(15/2), respectively. At the meantime, the fluorescence intensity ratio (FIR) variation of two green UC emissions at 526 and 547 nm has been studied as a function of temperature in the range of 153-603 K. The maximum sensor sensitivity obtained was 39 × 10~(-4) K~(-1) at 590 K, which indicated that Er~(3+)/Yb~(3+) co-doped CBT ceramic is a promising candidate for applications in optical high temperature sensor.