Strong luminescence induced by elastic deformation of piezoelectric crystals

The luminescence induced by elastic deformation of solids, called the phenomenon of elastico-mechanoluminescence (EML), is observed in several materials. For applied pressure in the range of 17 MPa, certain crystals emit intense EML, which can be seen in day light with naked eye. In the present paper, we explore that, as the piezoelectric constant near the photo-generated electric dipoles formed by trapping of charge carriers in crystals is several times higher as compared to that at normal sites, the piezoelectrically induced detrapping of charge carriers and EML emission may take place for less value of the pressure applied onto the crystals. (C) 2013 AIP Publishing LLC.