Near Infra-Red Mechanoluminescence from Strontium Aluminate Doped with Rare-Earth Ions

Mechanoluminescence (ML), an interesting luminescence phenomenon, is the light emission caused by mechanical stimuli such as grinding, cutting, collision, striking, friction, etc. Recently the ML phenomenon has attracted more attention due to its potential application for sensing structural damages, fractures, and deformations. So far various ML wavelengths from near-ultraviolet to red region have been achieved in our laboratory. However a ML material with a near infra-red (NIR) emission has still not been realized though there are many advantages for applications. In this study we successfully developed a ML material with a 1530 nm emission by co-doping Er ions in SrAl2O4:Eu2+. In addition we report the optical and the ML properties of SrAl2O4:Eu2+, SrAl2O4:Er3+, SrAl2O4:Eu2+, Er3+.