Intense and recoverable piezoluminescence in Pr3+-activated CaTiO3 with centrosymmetric structure

Abstract

Recoverable mechanoluminescence (RML) has shown attractive potential in diverse fields of stress sensors, lighting, displays, and bioexcitation. However, efficient RML materials are universally constructed with a noncentrosymmetric lattice as the matrix, encountering limitations in obtaining centrosymmetric lattice availability. In this work, we report an amazing RML in the well-known persistent phosphor CaTiO3:Pr3+ with a centrosymmetric structure, which exhibits intense, reproducible, and quantitative emission under the stimulation of mechanical compression and friction and even hand rubbing. The systematic investigations of thermoluminescence and piezoresponse force microscopy indicate that local piezoelectricity caused by structural defects plays a key role in detrapping the electrons captured by traps, thereby generating recoverable piezoluminescence in CaTiO3:Pr3+. Our results reveal the availability of the centrosymmetric lattice as the material matrix to achieve high-efficiency RML, which is expected to broaden the horizons of designing RML materials.