Antithermal-Quenching All-Inorganic Perovskite Crystals with Green Ultralong Persistent Luminescence for Advanced Anticounterfeiting Applications

Long persistent luminescence (PersL) materials have revolutionized many fields of optoelectronics and photonics due to their applications in anticounterfeiting, information encryption, and in vivo bioimaging. Here, we reported a novel PersL crystal prepared by the heterovalent doping of Sb³⁺ into perovskite tetragonal phase RbCdCl₃, comparing with the pristine non-perovskite orthorhombic phase analogue without PersL property. Surprisingly, under the UV light irradiation, the title crystals concurrently exhibit green ultralong PersL (>2400 s), high photoluminescence quantum yield (49.1%), and antithermal quenching in the range from 148 to 328 K. It was revealed by experimental results and theoretical analyses that green ultralong PersL and antithermal quenching of perovskite-phase RbCdCl₃/Sb³⁺ crystals originate from the electron transition between the 5s² level of the dopant Sb³⁺ and the electronic defect-induced trap states. Enlightened by the excellent optical properties, the tetragonal perovskite-phase RbCdCl₃/Sb³⁺ PersL materials show promising application prospects in anticounterfeiting and encryption of information.