Liu Meng, Zhu Jingyi, Zhao Guohui, Li Yuxuan, Yang Yupeng, Gao Kaimin, Wu Kaifeng
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
University of Chinese Academy of Sciences, Beijing, China.
Nat Mater. 2025 Feb;24(2):260-267. doi: 10.1038/s41563-024-02061-1. Epub 2025 Jan 6.
The interconversion between singlet and triplet spin states of photogenerated radical pairs is a genuine quantum process, which can be harnessed to coherently manipulate the recombination products through a magnetic field. This control is central to such diverse fields as molecular optoelectronics, quantum sensing, quantum biology and spin chemistry, but its effect is typically fairly weak in pure molecular systems. Here we introduce hybrid radical pairs constructed from semiconductor quantum dots and organic molecules. The large g-factor difference enables us to directly observe the radical-pair spin quantum beats usually hidden in previous studies, which are further accelerated by the strong exchange coupling of radical pairs enabled by the quantum confinement of quantum dots. The rapid quantum beats enable the efficient and coherent control of charge recombination dynamics at room temperature, with the modulation level of the yield of spin-triplet products reaching 400%.
光生自由基对的单重态和三重态自旋态之间的相互转换是一个真正的量子过程，可通过磁场对复合产物进行相干操纵。这种控制在分子光电子学、量子传感、量子生物学和自旋化学等多个领域至关重要，但在纯分子系统中其效应通常相当微弱。在此，我们引入了由半导体量子点和有机分子构成的混合自由基对。巨大的g因子差异使我们能够直接观测到以往研究中通常隐藏的自由基对自旋量子拍，而量子点的量子限域所产生的自由基对强交换耦合进一步加速了这种量子拍。快速的量子拍使得在室温下能够对电荷复合动力学进行高效且相干的控制，自旋三重态产物产率的调制水平达到400%。
