Halide exchange mediated cation exchange facilitates room temperature co-doping of d-and f-block elements in cesium lead halide perovskite nanoparticles

Abstract

This study presents a halide exchange mediated cation exchange reaction to co-dope d- and f-block elements in CsPbX₃ NPs at room temperature. Addition of MnCl₂ and YbCl₃ to CsPbBr₃ NPs induces ion exchange reactions generating the corresponding CsPbBr₃/MnCl₂YbCl₃ NPs. In addition to the perovskite emission, the NPs display sensitized Mn²⁺ and Yb³⁺ emissions in concert spanning the UV, visible, and NIR spectral region. Structural and spectroscopic characterizations indicate a substitutional displacement of Pb²⁺ by the Mn²⁺ and Yb³⁺. The identity of the host halide in modulating the ion exchange reactions was also tested. An effective perovskite host NP is presented that can be used to incorporate d–f or f–f dopant combinations to realize a gamut of dopant emission lines. A charge trapping based photophysical model is developed that focuses on rational energy alignments to predict dopant emissions semi-empirically and aids the design of optimal perovskite host−multi-dopant combinations.