Defect-management-induced multi-stimulus-responsive mechanoluminescence in Mn2+ doped gallate compound

Exploring mechanoluminescence (ML) materials having multi-stimulus-responsive luminescence is conducive to promoting the development of ML field applications. However, integrating the multi-stimulus-responsive luminescence into a single material is challenging, especially when concerning the unclear multi-stimulus-responsive luminescence mechanisms. Herein, we successfully synthesized a Mn2+-activated broadband multi-stimulus-responsive ML material in a non-centrosymmetric piezoelectric host (LiGaO2: Mn2+). Utilizing the defects' homology characteristic between ML and persistent/photo-stimulated luminescence, it is confirmed that one can manage the distribution and depth of defects to determine the internal relationship between the multi-stimulus-responsive luminescence and defects. Meanwhile, the V••o and V'Li defects and distribution play a dominant role in multi-mode luminescence. The dynamic process of multi-stimulus-responsive luminescence that charge carriers trapped in deep defects are supplemented to shallow defects can be proved by experimental and DFT calculation results. Based on the excellent multi-stimulus-responsive luminescence performance, the proof-of-concept multi-mode application prospects are demonstrated. This work will deepen our understandings of the multi-stimulus-responsive luminescence mechanism via regulating the distribution and composition of defects to further promote research on flexible X-ray detectors and anti-counterfeiting fields.