 1996 study by Matsuzawa et al. reported extremely long-lasting afterglow of senior al-204 EU2 plus codeped with di-3 plus ions, which was brighter than ZNS-CU company. Despite this discovery, the number of stable and efficient persistent phosphorus is still low, and the mechanism behind this phenomenon is unclear. This review presents an overview of known persistent luminescent materials based on EU2 plus emission and discusses suggested models and mechanisms for bright afterglow in various compounds. This article was authored by Kuhn Van Den Eekhout, Philippe F. Smet, and Dirk Palman.