Stabilization of Ti3+ in CaTiO3 by doping Y3+ to generate visible light-activated near-infrared persistent luminescence

Near-infrared (NIR) persistent luminescence (PersL) materials have interesting invisible self-luminescent properties, but most of them can only be effectively activated by UV light. In the present study, Ca0.97TiO3:Y0.02 (CaTiO3:Y) is found with visible-light-excited PersL at ∼770 nm lasting at least for 5 h. The PersL is derived from the broad absorption of Ti3+, which is stabilized by Y3+-doping via a charge compensation strategy. The PersL excitation spectrum has a peak at ∼ 400 nm, extending to 720 nm. Y3+-doping at Ca2+ site stimulates the generation of more oxygen vacancies and the stabilization of luminescent Ti3+. The Cr-free property makes CaTiO3:Y an environmentally friendly anti-counterfeiting luminescent material. The interaction between narrow band gap CaTiO3 and proper energy levels of Ti3+ is of vital importance in the successful development of visible-light-excited PersL materials. This study provides a new member of Cr-free NIR PersL material with intense visible-light-excited luminescent property and has certain guidance on developing other visible-light-excited PersL materials. •CaTiO3:Y0.02 was synthesized with visible-light-excited persistent luminescence at ∼770 nm.•The room-light-activated persistent luminescence lasted for more than 5 h.•The persistent luminescence was derived from Ti3+ emission.•Y3+ stabilized Ti3+ via charge compensation during the annealing synthesis process in air.•CaTiO3:Y0.02 has potential application as an environment-friendly anti-counterfeiting material.