Piezoluminescence from ferroelectric CaTiO:Pr long-persistent phosphor.

A variety of up-and-coming applications of piezoluminescence in artificial skins, structural health diagnosis, and mechano-driven lightings and displays recently have triggered an intense research effort to design and develop new piezoluminescent materials. In this work, we deduced and verified an efficient piezoluminescence in ferroelectric CaTiO:Pr long-persistent phosphor, in view of three fundamental elements forming piezoluminescence - piezoelectricity, luminescent centers and carrier traps. Under the stimulation of mechanical actions including compression and friction, CaTiO:Pr shows an intense red emission from D-H transition of Pr. On the basis of investigations on structural and optical characteristics especially photoluminescence, persistent luminescence and thermoluminescence, we finally proposed a possible piezoluminescent mechanism in CaTiO:Pr. Our research is expected to expand the horizon of existing piezoluminescent materials, accelerating the development and application of new materials.