UV-light activated blue-emitting persistent luminescence of CaYGaO4:Bi3+ suitable for high-temperature environment

The persistent luminescence (PersL) materials suitable for high-temperature environments have attracted extensive attention in recent years. Herein, we have reported a novel long-persistent luminescent material of CaYGaO4:Bi3+, with a peak wavelength of 430 nm and a duration of more than 40 min at room temperature at the 0.32 mcd/m2 threshold value after UV irradiation. A series of thermoluminescence measurements reveal that the CaYGaO4:Bi3+ phosphor has abundant shallow and deep traps with a wide range of distribution. In addition, we utilize the ion substitution strategy of Sr2+ partially replacing Ca2+ ions to increase the shallow trap concentration, so as to improve the performance of PersL at room temperature. More importantly, we investigate the PersL performance of CaYGaO4:Bi3+ phosphor at high-temperature environment. As the result demonstrates, when the ambient temperature is in the high-temperature range (450 K–600 K), the phosphor has more obvious brightness. Finally, we take advantage of the phosphor to carry out a demonstration experiment and obtain a set of temperature-related color conversion images, which unequivocally signifies that the phosphor has broad application prospects in anti-counterfeit fields and emergency indicator marks in high-temperature and harsh environments.