Tunneling in Persistent Luminescence

Abstract An overview of some key points in persistent luminescence (PersL) is provided with an emphasis on tunneling phenomena. Notably, key experimental criteria are provided that can substantiate the occurrence of thermal and athermal tunneling and localized transitions. These are elucidated by reference to a Case Study and to some other relevant works. Many experimental studies of PersL have assigned the mechanism to be tunneling on the basis of the linear relationship of PersL decay between intensity, I , and time, t −k , where k is a constant, or I −1 versus t . However, this relation also applies to the case where there is a uniform distribution of trap levels, which may be evident from the breadth of the TL peak. The key measurement for the assignment of below‐conduction band processes is the absence of thermal conductivity.