Photoluminescence and Electrical Properties of Er-doped (K0.5na0.5)nbo3-Based Transparent Ceramics

Er-doped 0.98(K0.5Na0.5)NbO3-0.02Ba(Bi0.5Nb0.5)O3 transparent fluorescent ceramics were prepared using traditional solid-phase method. The (K0.5Na0.5)NbO3 (KNN) ceramics were modified by introducing the second group elements Ba(Bi0.5Nb0.5)O3 and rare earth ions Er3+. The effects of Er3+ on the structure, optical and electrical properties of transparent ceramics (K0.5Na0.5)NbO3-Ba(Bi0.5Nb0.5)O3 were investigated. The ceramics form a single perovskite structure and have a pseudo-cubic phase structure. Nanoscale grain size was obtained for ceramics, and the smallest average grain size is 80 nm. The ceramics have high transmittance. The ceramic 0.1 mol% Er-doped 0.98(K0.5Na0.5)NbO3-0.02 Ba(Bi0.5Nb0.5)O3 achieved the highest transmittance for this system with 62% and 52% at near-infrared light (1000 nm) and visible light (700 nm), respectively. The ceramics have up-conversion luminescence properties and also maintain good electrical properties. Under 980 nm excitation, the samples showed two green emission bands (518–536 nm, 536–557 nm) and one red emission band (646–677 nm). In addition, the ceramics have relaxation ferroelectricity, and a high dielectric constant. These functional ceramics with multiple properties will have greater research significance and application value.