Exciton-to-Dopant Energy Transfer Dynamics in Mn²⁺ Doped CsPbBr₃ Nanowires Synthesized by Diffusion Doping

Mn²⁺ doped perovskite nanocrystals have garnered significant attention in optoelectronic applications. However, the synthesis of Mn²⁺ doped perovskite nanowires (NWs) poses challenges, and the dynamics of energy transfer from the exciton to Mn²⁺ remains unexplored, which is crucial for optimizing Mn²⁺ luminescence efficiency. Herein, we present a method to synthesize Mn²⁺ doped CsPbBr₃ NWs with a photoluminescence quantum yield of 52% by diffusing Mn²⁺ into seed CsPbBr₃ NWs grown via a hot injection method. We control the solution and lattice chemical potentials of Pb²⁺ and Mn²⁺ to enable Mn²⁺ to diffuse into the CsPbBr₃ NWs while minimizing Ostwald ripening. Variable temperature photoluminescence spectroscopy reveals that the energy transfer from the exciton to Mn²⁺ in Mn²⁺ doped CsPbBr₃ NWs is temperature dependent. A dynamic competition is observed between energy transfer and backward energy transfer, resulting in stronger Mn²⁺ photoluminescence at 80 K. This work provides a specific synthesis pathway for Mn²⁺ doped CsPbBr₃ NWs and sheds light on their exciton-to-Mn²⁺ energy transfer dynamics.