BLUE LIGHT EMISSION FROM STRESS-ACTIVATED SR2MGSI2O7:EU

We discovered that Sr2MgSi2O7:Eu phosphor emits blue light under the application of a mechanical stress, a phenomenon known as mechanoluminescence (ML). The ML showed a similar spectrum as photoluminescence (PL), which indicated that ML is emitted from the same center of Eu2+ ions as PL. The analysis of structure and thermoluminescne suggested that the origin of ML for Sr2MgSi2O7:Eu phosphor can be attributed to strain-induced electroluminescence, that is, piezoelectricity impelled the trapped electrons to escape from the trap and produce ML. Furthermore, the relation between ML intensity and compressive load is close to linearity, which indicate that this sample can be used for smart-skin and self-diagnosis applications.