A Universal Strategy for Multicolor Mechanoluminescence via Radiative Energy Transfer Based on Ultraviolet Mechanoluminescent Material Ca9Al(PO4)7:Ce3+

Abstract The selection of mechanoluminescent materials is often unpredictable and arbitrary, posing new challenges for the application of high‐performance mechanoluminescence (ML). Materials with exceptional photoluminescence (PL) properties generally possess highly efficient carrier radiative transitions. Investigating how to induce ML in these materials can provide new perspectives on the selection of ML materials. Here, a universal strategy for multicolor ML via radiative energy transfer by ultraviolet ML material Ca 9 Al(PO 4 ) 7 :Ce 3+ (CAPC) is proposed. Multicolor ML can be regulated through the isomerization of energy acceptors. In CAPC@energy acceptor@polydimethylsiloxane composite system, the multicolor ML relies on a simple radiative energy transfer (reabsorption) mechanism, rather than the complex energy transfer between the excited states of ions. Using this strategy, certain highly efficient PL materials can develop ML, transitioning from nonexistent to present or from weak to strong. Additionally, the ML color can be tuned by adjusting the composition ratio of energy donor and acceptor. This work provides a simple, feasible, and versatile strategy for the selection and development of multicolor ML materials.