Creating visible-to-near-infrared mechanoluminescence in mixed-anion compounds SrZn2S2O and SrZnSO

Mechanoluminescence (ML) materials featuring light emission in response to mechanical stimulus have shown promising applications in damage diagnosis, dynamic force detection, and information storage. However, their applications are greatly limited by a very small number of available ML materials as well as unsatisfied ML spectra. In this paper, we developed novel ML materials with intense ML and super-broad visible-to-near-infrared (470-1600 nm) spectra by incorporating lanthanide ions or transition metals into mixed-anion compounds SrZn2S2O and SrZnSO. These mixed-anion compounds show a linear relationship between ML intensity and applied force, allowing them to be used in non-contact/multi-touch stress sensing. Moreover, the mixed-anion compounds exhibit multiband near-infrared ML enabling a significant bright-field stress sensing approach without the interference of ambient light. This work offers a unique insight for discovering new ML materials and enriching the ML spectral range, thereby promoting their potential applications in stress intelligent sensors, electronic skins, and human-machine interfaces.