Exciton-to-Dopant Energy Transfer Dynamics in Mn 2+ Doped CsPbBr 3 Nanowires Synthesized by Diffusion Doping.

Mn 2+ doped perovskite nanocrystals have garnered significant attention in optoelectronic applications. However, the synthesis of Mn 2+ doped perovskite nanowires (NWs) poses challenges, and the dynamics of energy transfer from the exciton to Mn 2+ remains unexplored, which is crucial for optimizing Mn 2+ luminescence efficiency. Herein, we present a method to synthesize Mn 2+ doped CsPbBr 3 NWs with a photoluminescence quantum yield of 52% by diffusing Mn 2+ into seed CsPbBr 3 NWs grown via a hot injection method. We control the solution and lattice chemical potentials of Pb 2+ and Mn 2+ to enable Mn 2+ to diffuse into the CsPbBr 3 NWs while minimizing Ostwald ripening. Variable temperature photoluminescence spectroscopy reveals that the energy transfer from the exciton to Mn 2+ in Mn 2+ doped CsPbBr 3 NWs is temperature dependent. A dynamic competition is observed between energy transfer and backward energy transfer, resulting in stronger Mn 2+ photoluminescence at 80 K. This work provides a specific synthesis pathway for Mn 2+ doped CsPbBr 3 NWs and sheds light on their exciton-to-Mn 2+ energy transfer dynamics.