Electron Tunneling Charging upon Sunlight for Near‐Infrared Persistent Luminescence

Abstract

AbstractFor 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 GaII‐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.