Interfacial Interaction Modulated Radiation Defects for Self-Charging Persistent Mechanoluminescence

Self-charging persistent mechanoluminescence (SC-PML) is of particular interest for stress sensing/visualization applications, as it not only notably extends the time window available for stress observation, but also avoids the pre-charging with great convenience. However, the intrinsic physical principles of the SC-PML are still unclear. Herein, a phosphor Sr₉LiMg(PO₄)₇: Dy³⁺ with an initially clean trap structure is reported to exhibit repeatable SC-PML up to 30 s when incorporated into a flexible polydimethylsiloxane. The observed divergence between the SC-PML and the transient photoluminescence provides a unique insight in terms of the mechanics-induced trap creation for delving into the fundamental mechanisms. The muti-mode stimuli/irradiation tests further suggest the presence of a high-energy process at interface associated with the mechanoluminescence. This process is capable of producing effects analogous to those of X-ray irradiation, and sufficient to facilitate the generation of trapping centers within Sr₉LiMg(PO₄)₇: Dy³⁺ lattice. The above findings provide a clear insight for SC-PML, and the as-developed SC-PML material is further applied for the multi-mode anticounterfeiting and stress-sensing devices as representatives.