Emission color-tunable and optical temperature sensing properties of Er3+/La3+ co-doped (K0.5Na0.5)NbO3 optoelectronic transparent ceramic

Abstract Transparent Er 3+ /La 3+ co-doped (K 0.5 Na 0.5 )NbO 3 ceramic was prepared by pressureless sintering. The XRD result shows that it possesses high symmetrical pseudo-cubic perovskite structure without impurity phase. The ceramic owns fine grains with the average size of ∼350 nm, uniform grain distribution, low porosity and high density. The optical transmittance of 0.3-mm ceramic is up to ∼60% in the visible region. Additionally, the ceramic has good dielectric properties with the relaxor-like behavior. Under an excitation of 980-nm, the temperature-dependent up-conversion luminescent color of Er 3+ is stable below 523 K and adjustable (changing from green to tangerine color as temperature increases) above 523 K. The ratio of red to green emission intensity with temperature can provide a non-contact luminescent route to roughly detect the phase transition of this ferroelectric ceramic. Furthermore, the fluorescence temperature sensing performance of the ceramic was investigated and the maximum sensitivity is 0.003/K at 380 K. Due to optical, PL and electrical properties, the transparent ceramic shows potential in the application of electro-optical coupling devices.