Recent progress in multicolor long persistent phosphors

► A new orange-yellow long persistent phosphor Sr3Al2O5Cl2:Eu2+, Tm3+ was found. ► A new red long persistent phosphor Sr2SnO4:Sm3+ was found. ► A novel silicate long persistent phosphor was found. ► The photoionization of Eu2+ to Eu3+ was found in BaMgSiO4.