钙钛矿受限量子体系相干动力学的多维电子光谱研究

Excitonic transitions in strongly confined perovskite semiconductors show behaviors similar to quantum two-level systems, which are promising for applications in single-photon emitters and light-emitting diodes. In this project, we propose to study the quantum coherent dynamics in such strongly confined systems using multi-dimensional electronic spectroscopy (MDES). By manipulating phases, amplitudes, polarizations and spectra of ultrashort pulses employed in the technique of MDES, we plan to investigate the dephasing mechanisms of excitonic transitions, analyze the fine structures of excitonic levels including the bright and dark states, and explore the possible quantum phases induced by high-order correlations due to many body interactions. The project can potentially uncover new insights about the light-matter interaction between ultrashort pulses and strongly confined systems and provide pivotal knowledges about the quantum dynamics in perovskite nanocrystals and quantum wells, which may advance their applications in the field of quantum information and optoelectronics.

钙钛矿半导体受限量子系统的激子跃迁展现了类二能级系统的行为，在单光子源、发光二极管等领域具有美妙的应用前景。本项目中，我们计划利用多维量子相干光谱学方法研究钙钛矿半导体受限系统中的量子相干动力学。借助超快光场位相、幅度、偏振和频谱调控的多维相干电子光谱学，探究光场与钙钛矿半导体受限系统的相互作用，检测这类新型受限系统的激子能级的光谱展宽和退相干机制，分析激子能级的精细结构，特别关注明暗激子态的能级位置和动力学过程，探索多激子作用可能引起的高阶关联和量子物态。预期结果将加深超短脉冲与受限体系相互作用的理解，促进学界对钙钛矿半导体受限系统量子动力学的理解，推动其在量子信息和光电器件领域内的应用。

项目计划发展多维量子相干光谱学方法，并用以研究钙钛矿半导体受限系统中的量子相干动力学。借助超快光场位相、幅度、偏振和频谱调控的多维相干电子光谱学，探究光场与钙钛矿半导体受限系统的相互作用，检测这类新型受限系统的激子能级的光谱展宽和退相干机制，分析激子能级的精细结构，探索多激子作用可能引起的高阶关联和量子物态。项目组解决了二维电子光谱测试时间分辨的兼容性以及少周期脉冲偏振位相调控的结合实现了不同温度下钙钛矿量子点中双激子态的特征，测量了双激子束缚能随温度及尺寸的变化，表征了钙钛矿量子点中自旋退相干的光谱学特征，观察到热载流子弛豫的量子受限效应；进一步拓展结合磁场，实现瞬态磁光光谱测试平台，并系统研究分子光电材料中三线态在激发态动力学中的重要效应。研究结果发表在Nature Chemistry, Nature Communications, J. Am. Chem. Soc., J. Phys. Chem. Lett. 等，相关技术进步申请获批技术发明两项。