Deep trap assisting elastico-mechanoluminescence in diphase non-piezoelectrics induced by tunneling effect

The sustainable conversion of mechanical energy into light (elastico-mechanoluminescence, EML) opens up possibilities for energy-saving, which is of pivotal significance in addressing the energy crisis. The concepts of piezophotonics and the piezoelectric field's dependence on the probability of charge carriers detrapping have been thoroughly developed in explaining EML. Nevertheless, in contrast to the EML triggered by the piezoelectricity model, strong elastico-mechanoluminescence phenomena have also been frequently discovered in non-piezoelectric materials. Is the working principle different? This paper provides physical insight into the reconfigurable EML phenomena of intrinsic non-piezoelectric systems. It emphasizes the exploration of the mechanism through comprehensive analysis of trap information, de-trapping processes, and the lifetime of charge carriers in traps. We demonstrate the assistance of deep trap to enhance the red EML mode in a diphase centrosymmetric luminescent host through the electron tunneling effect. This advancement supports the progress of non-piezoelectric EML dielectrics and offers an appealing alternative approach in this field.