Wu Fan, Nguyen-Phan Tu C, Cogdell Richard, Pullerits Tönu
Division of Chemical Physics and NanoLund, Lund University, Lund, Sweden.
School of Infection and Immunity, University of Glasgow, Glasgow, UK.
Nat Commun. 2025 Jun 12;16(1):5300. doi: 10.1038/s41467-025-60616-5.
Excitation energy transfer between photosynthetic light-harvesting complexes is vital for highly efficient primary photosynthesis. Controlling this process is the key for advancing the emerging artificial photosynthetic systems. Here, we experimentally demonstrate the enhanced excitation energy transfer between photosynthetic light-harvesting 2 complexes (LH2) mediated through the Fabry-Pérot optical microcavity. Using intensity-dependent pump-probe spectroscopy, we analyse the exciton-exciton annihilation (EEA) due to inter-LH2 energy transfer. Comparing EEA in LH2 within cavity samples and the bare LH2 films, we observe enhanced EEA in cavities indicating improved excitation energy transfer via coupling to a common cavity mode. Surprisingly, the effect remains even in the weak coupling regime. The enhancement is attributed to the additional connectivity between LH2s introduced by the resonant optical microcavity. Our results suggest that optical microcavities can be a strategic tool for modifying excitation energy transfer between molecular complexes, offering a promising approach towards efficient artificial light harvesting.
光合捕光复合物之间的激发能量转移对于高效的初级光合作用至关重要。控制这一过程是推进新兴人工光合系统的关键。在此，我们通过实验证明了通过法布里 - 珀罗光学微腔介导的光合捕光2复合物（LH2）之间增强的激发能量转移。使用强度依赖的泵浦 - 探测光谱，我们分析了由于LH2间能量转移导致的激子 - 激子湮灭（EEA）。比较腔体内样品中的LH2和裸LH2薄膜中的EEA，我们观察到腔体内EEA增强，表明通过耦合到共同的腔模，激发能量转移得到改善。令人惊讶的是，即使在弱耦合 regime中该效应仍然存在。这种增强归因于共振光学微腔引入的LH2之间的额外连通性。我们的结果表明，光学微腔可以成为修饰分子复合物之间激发能量转移的战略工具，为高效人工光捕获提供了一种有前景的方法。
