Mechanoluminescence spectrum tuning from zinc sulfide and all-inorganic perovskite quantum dots composite

Mechanoluminescence (ML) materials exhibit great potential in the fields of light sources, displays, and stress sensors because they can convert mechanical stimuli into luminescence. Most ML materials exhibit weak brightness and limited colors; therefore, tunable colors are highly desired. Herein, a facile strategy for tuning the ML of a flexible composite of zinc sulfide (ZnS) phosphor and all-inorganic CsPbX3 (X = Cl, Br, and I) perovskite quantum dots (PeQDs) is demonstrated. A broad color expression with a narrow emission band was achieved under low stretching–releasing stress by changing the halide component of CsPbX3. The color conversion between ZnS and PeQDs is a radiative combination and reabsorption process, and full color tuning from 510 to 710 nm occurred because of the bandgap tailoring of PeQDs. Furthermore, some proof-of concept devices, including multicolor displays and white light sources, were demonstrated by changing the composition of PeQDs. This work provides a versatile approach to fine–tune the ML spectrum, thereby paving the way for applications such as piezophotonic displays and white light sources.