Nearly‐Unity Quantum Yield and 12‐Hour Afterglow from a Transparent Perovskite of Cs<sub>2</sub>NaScCl<sub>6</sub>:Tb
Xiaojia Wang, Xiangzhou Zhang, Shao Yan, Hong Liu, Yuhai Zhang
Abstract
Abstract Unlike afterglow phosphors, transparent crystals free of scattering issues hold great potential in applications such as volumetric displays and three‐dimensional encryption. Here, a double‐perovskite host of ca. 85 % transparency, a Cs 2 NaScCl 6 single crystal, was grown in aqueous solution. Through heavy doping of Tb ions, the crystal exhibited a high photoluminescence quantum yield (PL QY) up to 98.2 %. Both steady‐state and transient PL spectroscopic investigation revealed a cross‐relaxation efficiency ( η CR ≈99 %) between Tb ions, greatly mitigated the electron saturation on the 5 D 3 level and encouraged the radiative route against quenching. The doped crystal displayed an intense afterglow of up to 12 h after ceasing the X‐ray excitation, allowing it to be used in a radiation‐storage battery which has a linear scaling capacity with loading weight. Our work opens possibilities in photo‐stimulated volumetric display and three‐dimensional information storage.