Time-Resolved Spectroscopic Investigation of Charge Carrier Dynamics in Metal Bromide Perovskites for Photocatalytic CO₂ Reduction

Ying-Chih Pu^1*

¹Department of Materials Science, National University of Tainan, Tainan, Taiwan

* Presenter:Ying-Chih Pu, email:ycpu@mail.nutn.edu.tw

Photocatalytic conversion of CO₂ into chemical fuels or valuable chemicals has emerged as a promising strategy to mitigate carbon emissions. In this process, the photon-harvesting ability and photoelectric conversion efficiency of the photocatalyst are key factors governing the overall CO₂ conversion performance. Metal bromide perovskite nanoheterostructures (NHSs) have recently shown great potential for photocatalytic CO₂ reduction owing to their strong light absorption under sunlight, long charge carrier diffusion lengths, and tunable band structures enabled by compositional engineering. Nevertheless, the mechanisms responsible for their outstanding photoactivity remain insufficiently understood. In this talk, a series of CsPbBr₃-based perovskite NHSs will be introduced, including CsPbBr₃/g-C₃N₄, CsPbBr₃/graphene, and CsPbBr₃/carbon quantum dot (CQD) composites, which exhibit excellent photocatalytic CO₂ conversion performance. To elucidate the underlying mechanisms, we systematically investigated their surface chemical properties, electronic band structures, and interfacial charge carrier dynamics using transient absorption and time-resolved photoluminescence spectroscopies. This study provides new and valuable insights into the charge transfer processes of semiconductor nanoheterostructures for solar-driven CO₂ conversion.

Keywords: Time-resolved Spectroscopies, Charge carrier dynamics, Perovskite, Photocatalytic CO₂ reduction