Investigation on photoluminescence and photochromism in Eu³⁺-doped (Ba_1-xCa_x)TiO₃

We investigated the photoluminescence (PL) and photochromic (PC) properties of ferroelectric (Ba_1-xCa_x)TiO₃ (BCT, x = 0.14 and 0.16) with the doping of Eu³⁺. To assess the effect of the Eu³⁺-doping sites on the luminescent properties, we prepared two types of samples: substitutional and interstitial dopings. We confirmed that our samples exhibited sizable luminescent properties without losing their ferroelectric properties. We observed that interstitial doping was more effective in achieving luminescent ferroelectrics in BCT compared to substitutional doping. We identified the PC behavior and the related PL modulation in Eu³⁺-doped BCT. The decrease in the reflectivity in the visible region and the suppression of PL intensity were maximized under the UV light irradiation at 380 nm.