Intense and efficient green mechanoluminescence in CaLaAl₃O₇ through Tb³⁺ doping

In this work, an efficient mechanoluminescent material with green emitting color, CaLaAl3O7:Tb3+, is reported. The mechanoluminescent intensity of CaLaAl3O7:Tb3+ is dependent on the content of luminescent centers, and the optimum doping concentration of Tb3+ is determined to be 6.0%, whatever the sample is stimulated by stretching or rubbing. The temperature-dependent properties suggest that the mechanoluminescence of CaLaAl3O7:Tb3+ should come from the released carriers from traps under stress stimuli, and therefore the underlying mechanoluminescent mechanisms of CaLaAl3O7:Tb3+ is revealed. By comparing with the commercial ZnS:Cu, a well-known mechanoluminescent material with high efficiency, the CaLaAl3O7:Tb3+ exhibits an even higher intensity when tested at the same conditions. It suggests that CaLaAl3O7:Tb3+ is a very efficient mechanoluminescent material, showing promising applications in the new generation of lighting, displaying and sensing devices.