Optical behavior of Pr~(3+)-doped barium titanate-calcium titanate material prepared by sol-gel method

摘要

Photoluminescence performances of Pr-doped alkaline-earth titanates (Ba,Ca)TiO_3 (with rich barium) prepared by a sol-gel technique are investigated at room temperature. A relatively strong red luminescence is observed in (Ba_(0.80)Ca_(0.20))TiO_3 material when Pr-BaTiO_3 material does not exhibit obvious red luminescence. The phenomenon is discussed with respect to the substitute of Ca and the two-photon luminescence effect. The red luminescence is enhanced by a fast thermal treatment. The wavelength range of luminescence near red and infrared light is broadened by the same process as well. These behaviors are ascribed to the randomization of distribution of Ca and Ba at A site in ABO_3 perovskite structure. The experimental results provide not only a possible way to develop new materials with pastel visual impression, but also a potential technique to modify photoluminescence properties that can be controlled by external fields because the microscopic structure of BaTiO_3, such as electric domains, can be changed by electric field, temperature, and so on.