Modulation of Mechanical Quenching Properties and Analysis of the Mechano‐Optical Conversion Mechanism in ZnS

Abstract

ABSTRACT Mechano‐optical responsive materials exhibit changes in luminescence intensity upon mechanical stimulation, demonstrating efficient force‐to‐optical conversion characteristics. These materials hold broad application prospects in areas such as stress sensors, flexible wearable devices, anti‐counterfeiting, and encryption. Depending on the variation of luminescence intensity under mechanical force, mechano‐optical responsive materials can be classified into mechanoluminescence (ML) and mechanical quenching (MQ). MQ refers to the phenomenon in which luminescence intensity is quenched upon the application of mechanical force. Since it was first reported in 2015, only a few materials, such as ZnS, ZnS:Mn 2+ , and the oxysulfide CaZnOS:Cu + , have been shown to exhibit this property. However, the detailed mechanism remains to be elucidated, and practical applications are still limited, which hinders further progress in this field. To gain deeper insight into the MQ property and its underlying mechanism, this research focuses on the simple system of undoped ZnS. By modulating the mechano‐optical response of ZnS and designing various stress modes, we further analyzed the diverse defects and structural changes and established a physical model for MQ.