Vibrational control (VC) of photochemistry through the optical stimulation of structural dynamics is a nascent concept only recently demonstrated for model molecules in solution. Extending VC to state-of-the-art materials may lead to new applications and improved performance for optoelectronic devices. Metal halide perovskites are promising targets for VC due to their mechanical softness and the rich array of vibrational motions of both their inorganic and organic sublattices. Here, we demonstrate the ultrafast VC of FAPbBr₃ perovskite solar cells via intramolecular vibrations of the formamidinium cation using spectroscopic techniques based on vibrationally promoted electronic resonance. The observed short (~300 fs) time window of VC highlights the fast dynamics of coupling between the cation and inorganic sublattice. First-principles modelling reveals that this coupling is mediated by hydrogen bonds that modulate both lead halide lattice and electronic states. Cation dynamics modulating this coupling may suppress non-radiative recombination in perovskites, leading to photovoltaics with reduced voltage losses.

通过结构动力学的光刺激对光化学进行振动控制 （VC） 是一个新兴的概念，最近才在溶液中的模型分子中得到证明。将 VC 扩展到最先进的材料可能会为光电器件带来新的应用和更高的性能。金属卤化物钙钛矿因其机械柔软性以及无机和有机亚晶格的丰富振动运动而成为 VC 的有前途的目标。在这里，我们使用基于振动促进电子共振的光谱技术，通过甲脒阳离子的分子内振动展示了 FAPbBr₃ 钙钛矿太阳能电池的超快 VC。观察到的 VC 短时间窗口 （~300 fs） 突出了阳离子和无机亚晶格之间耦合的快速动力学。第一性原理模型表明，这种耦合是由调节卤化铅晶格和电子态的氢键介导的。调节这种耦合的阳离子动力学可能会抑制钙钛矿中的非辐射复合，从而导致电压损失降低的光伏。