Antithermal-Quenching\nAll-Inorganic Perovskite Crystals\nwith Green Ultralong Persistent Luminescence for Advanced Anticounterfeiting\nApplications

Long persistent luminescence (PersL) materials have revolutionized\nmany fields of optoelectronics and photonics due to their applications\nin anticounterfeiting, information encryption, and in vivo bioimaging.\nHere, we reported a novel PersL crystal prepared by the heterovalent\ndoping of Sb<sup>3+</sup> into perovskite tetragonal phase RbCdCl<sub>3</sub>, comparing with the pristine non-perovskite orthorhombic\nphase analogue without PersL property. Surprisingly, under the UV\nlight irradiation, the title crystals concurrently exhibit green ultralong\nPersL (>2400 s), high photoluminescence quantum yield (49.1%),\nand\nantithermal quenching in the range from 148 to 328 K. It was revealed\nby experimental results and theoretical analyses that green ultralong\nPersL and antithermal quenching of perovskite-phase RbCdCl<sub>3</sub>/Sb<sup>3+</sup> crystals originate from the electron transition\nbetween the 5s<sup>2</sup> level of the dopant Sb<sup>3+</sup> and\nthe electronic defect-induced trap states. Enlightened by the excellent\noptical properties, the tetragonal perovskite-phase RbCdCl<sub>3</sub>/Sb<sup>3+</sup> PersL materials show promising application prospects\nin anticounterfeiting and encryption of information.