Effects of temperature on the mechano luminescence of gold-doped ZnS phosphors

The present paper reports the effects of temperature on the mechanoluminescence (ML) intensity of gold-doped ZnS phosphors. The ML intensity decreases with temperature and follows the relation I-T = I-T(0)(1 - T/T-c)(n) the value of it lies between 0.90 and 1.10 for ZnS phosphors. Generally, ML of ZnS phosphors ceases much below their melting point. The process of thermal quenching in the ML can be understood by electro and photoluminescence (PL) studies. The faster rate of decrease of ML intensity than the PL intensity suggests that in addition to increase in the non-radiative transition probability, the temperature also affects some other parameters such as piezoelectric constant or surface charge density responsible for the ML excitation.