Design of Ratiometric Dual‐Emitting Mechanoluminescence: Lanthanide/Transition‐Metal Combination Strategy

Abstract Mechanoluminescence (ML) materials with the ability to convert mechanical stimulate into visible light signals have enabled visualized mechanics sensing. To this point, stress sensing based on ML color is preferred over that based on ML intensity in terms of both sensing reliability and visual sensitivity. In this work, a ratiometric dual‐emitting ML strategy to realize the stress‐sensitive ML color variation, where the Lanthanide/transition‐metal combination is adopted to build the dual‐activator ML system is proposed. The difference in electronic configuration between Lanthanide and transition‐metal ions leads to the significant discrepancy in the response of corresponding luminescence kinetics to the instantaneous change of local crystal field environment induced by stress, which plays a key role in the strategy. This strategy establishes a new general path for the design of novel ratiometric ML materials.