Optimizing Energy Transfer: Suppressing Cs<sub>2</sub>ZnCl<sub>4</sub> Self‐Trapped States and Boosting Ce<sup>3+</sup> Ion Luminescence Efficiency
Ziying Wen, Yunfei Bai, Qichao Meng, Hongyuan Zhao, Qiujie Wang, Haibo Sun, Lixin Huang, Dan Huang, William W. Yu, Jun Zhu, Feng Liu
Abstract
Abstract Incorporating trivalent cerium ions (Ce 3+ ) into colloidal semiconductor nanomaterials, such as zinc sulfide (ZnS) and cesium lead chloride (CsPbCl 3 ), provides a feasible approach for achieving significant Ce 3+ photoluminescence (PL). However, due to inefficient intersystem crossing and intense non‐radiative decay of host phosphors, most Ce 3+ ‐doped luminophores exhibit low luminescence efficiency, with photoluminescence quantum yield (PLQY) typically <50%. Additionally, these doping systems often encounter challenges with spectral impurity due to unwanted fluorescence emanating from the host material. In this study, an optimal cesium zinc chloride (Cs 2 ZnCl 4 ) nanorod (NR) host matrix is meticulously engineered, that significantly enhances the luminescence of Ce 3+ ions, reaching a PLQY near unity. Furthermore, these NRs display an exceptionally pure Ce 3+ emission spectrum, free from any extraneous emission from the matrix itself. The results from transient absorption and emission experiments reveal a ≈100% energy transfer efficiency from Cs 2 ZnCl 4 to Ce 3+ , coupled with a significant reduction in radiative self‐trapped states within the host.