Experimental insight into the thermal quenching of the Tb3+ ion’s green photoluminescence in CaWO4 host

Abstract

By directly exciting the Tb3+ ion’s 7F6-5D4 absorption line, the 5D4-7F5 emission underwent a serious thermal quenching from 333 to 813 K in CaWO4 host. Through steady-state rate equation, it was shown in addition to the 5D4 state’s lifetime, the 7F6 state’s population also affected this thermal quenching. When using a diode laser at 405 nm to excite the Tb3+ ion’s second lowest 7F5 state, the 5D4-7F5 emission increased dramatically from 333 to 813 K. It reveals the thermal population from the lowest 7F6 ground state to the higher 7F5 state is one of the possible thermal quenching channels for the 5D4-7F5 emission.