Laser & Photonics Reviews 2023, 02, 08, https://doi.org/10.1002/lpor.202200999

For the conventional persistent luminescence (PersL) charging processes, carriers are photo-pumped to the conduction band (CB) or high-energy excited states (HES) under short-wavelength UV or coherent near-infrared (NIR) laser excitation. Herein, electron tunneling charging behavior is reported in Cr³⁺, Sm³⁺ co-doped NIR PersL magnetoplumbite SrGa₁₂O₁₉, which allows for efficient charging by incoherent visible light. First, the electrons are efficiently captured by the neighboring Ga^II-O²⁻ electron–hole trap centers via a tunneling process, and then these excited electrons are transferred to shallow traps via a persistently energetic optical pump. This work further optimizes the PersL performance via engineering the energy band through partial substitution of In³⁺ for Ga³⁺. Consequently, tunneling charging occurring near the neighboring Cr³⁺-traps dimers enables Sr(Ga,In)₁₂O₁₉:Cr³⁺,Sm³⁺ to display brighter NIR PersL (≈760 nm, peak; ≈100 nm, FWHM) than gallate spinel under sunlight irradiation. This work provides insights into electron tunneling charging under low-energy excitation for NIR PersL, which may inspire more PersL explorations for practical applications.