【学术报告】Vibronic Couplings in Solar Energy Conversion and Environmental Issues
日期：2024-05-24
阅读：152
主题：Vibronic Couplings in Solar Energy Conversion and Environmental Issues
报告人：饶毅，副教授，犹他州立大学化学与生物化学系
时间：2024年5月24日（周五）14:00
地点：徐名材报告厅（霞光楼200）
邀请人：严畅 副教授
个人简介
饶毅，副教授，终身职位，犹他州立大学化学与生物化学系。2003年博士毕业于中国科学院化学研究所。 2004年加入哥伦比亚大学化学系Eisenthal研究组进行三年博士后研究工作。随后以副研究员 (Associate Research Scientist)的身份与Nicholas J. Turro教授和Kenneth B. Eisenthal教授一起合作。2014年加入天普大学化学系以研究副教授 (Research Associate Professor) 的身份开始独立的研究工作。2017年在犹他州立大学化学与生物化学系以助理教授身份建立独立的研究小组。2023年晋升为副教授并授予终身职位。研究兴趣涉及超快光谱，表面科学，光化学, 能源转换，催化以及环境科学等诸多领域。以通讯联系人在Nature chemistry， PNAS， Communication Chemistry, ACS Energy Letter, J. Phys. Chem. Lett., J. Phys. Chem， and J. Chem. Phys. 等著名期刊上发表论文60余篇, 拥有美国专利5项。获得美国自然科学基金早期职业奖，美国化学会犹他分会杰出教育奖，本田汽车材料研究所优秀合作奖，犹他州立大学科学学院年度研究奖。
报告摘要
Interactions of electronic and vibrational degrees of freedom, namely vibronic couplings, are essential for understanding excited states relaxation pathways of molecular systems in bulk and at interfaces and surfaces. In this talk, I will give two examples of vibronic couplings applied to singlet fission and interfacial charge transfer. Part I: We examined the role of vibronic coupling in singlet fission using polarized transient absorption microscopy for solar energy conversion. It was found that singlet fission in pentacene is greatly facilitated by the vibrational coherence of a low frequency phonon, which anisotropic coherence persists extensively for a few picoseconds. This coherence-preserving phonon that drives the anisotropic singlet-fission is made possible by a unique cross-axial charge transfer intermediate state. In the same fashion, this phonon was also found to predominantly drive the quantum decoherence of a correlated triplet pair to form a decoupled triplet dimer. Part II: I will present the development of interface-specific two-dimensional electronic-vibrational sum frequency spectroscopy (2D-EVSFG) for electronic-vibrational couplings for excited states at interfaces and surfaces for environmental issues. We demonstrate this 2D-EVSFG technique by investigating photoexcited interface-active molecules at the air/water interface as an example. Our 2D-EVSFG experiments show strong vibronic couplings of interfacial molecules upon photoexcitation and subsequent relaxation of a locally excited (LE) state. We believe that this development of 2D-EVSFG opens up a new avenue of understanding excited state dynamics related to interfaces and surfaces.
