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

This study presents a halide exchange mediated cation exchange reaction to co-dope d- and f-block elements in CsPbX 3 NPs at room temperature. Addition of MnCl 2 and YbCl 3 to CsPbBr 3 NPs induces ion exchange reactions generating the corresponding CsPbBr 3 /MnCl 2 YbCl 3 NPs. In addition to the perovskite emission, the NPs display sensitized Mn 2+ and Yb 3+ emissions in concert spanning the UV, visible, and NIR spectral region. Structural and spectroscopic characterizations indicate a substitutional displacement of Pb 2+ by the Mn 2+ and Yb 3+ . 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.