A Review of Mechanoluminescence Based on Quaternary Oxysulfides: Research Progress, Mechanism and Applications

Mechanoluminescence (ML), a process that converts external mechanical energy into light energy, offers a solution to challenges in the area of energy saving by not requiring a load power supply. From the 17th century, when people started to explore this field, from the fracture luminescence of materials to the emergence of elastic-ML (EML) materials, there has been a great deal of research into the mechanisms and applications of ML. Piezoelectric properties are extremely important for ML materials, and most ML materials today have piezoelectric properties. Among them, quaternary oxysulfides M(Ca, Sr, Ba)Zn_xS_xO (x = 1, 2) are wide bandgap piezoelectric semiconductors developed in the 21st century. The doping of transition elements, trivalent lanthanides, and other metal-emitting ions has been realized in the last 20 years of development, and all of them show excellent ML properties. Quaternary oxysulfides have become significant inorganic mechanoluminescent materials. This article provides a detailed description of the development process, mechanism, performance optimization, and applications of quaternary oxysulfides, and highlights future trends and challenges.