Strong Photoluminescence and Improved Electrical Properties in Eu-Modified SrBi4Ti4O15 Multifunctional Ceramics

A red-emitting piezoelectric ceramic of SrBi4−xEuxTi4O15 (SBT-xEu, x = 0.000–0.010) with strong photoluminescence and improved piezoelectric properties was prepared. All samples had a bismuth oxide layered structure with a dense microstructure. After Eu3+ doping, a bright red photoluminescence upon blue light excitation of the 400 nm to 500 nm was observed in the modified samples. Upon the excitation of 465 nm light, the emission peaks centered at 537–703 nm were noted, which correspond to a weak green 5D1 → 7F1 transition and the characteristic emission bands (5D0 → 7FJ, J = 1–4). Simultaneously, Eu3+ doping promotes electrical properties. At 0.6 mol.% Eu, samples exhibit the optimal electric properties (d33 = 22 pC/N, 2Pr = 19.86 μC/cm2 and Tc = 534°C), together with excellent temperature stability (25–450°C). As a multifunctional material, Eu-doped SBT ferroelectric oxide showed great potential in sensors and optical-electro integration device applications.