On November 19, 2023, the Photonic Nose and Molecular Materials Group held an academic seminar in the lecture hall of the Institute of New Concept Sensors and Molecular Materials. Teachers and graduate students of the Institute attended the seminar, which was moderated by Prof. Bian Hongtao.

Liu Xinfeng, a researcher at the National Nanoscience Center of the University of Chinese Academy of Sciences, gave a report titled “Micro-scale Ultrafast Spectroscopy and Its Applications”. Ultrafast spectroscopy is an important technique to characterize charge carriers, which has been widely used in materials, information, physics, chemistry and other fields. He introduced a self-developed micro-scale steady-state/transient/angular resolution spectral measurement system with spatial, temporal and momentum resolution, which was applied to semiconductor material systems to test its carrier characteristics, electron phonon coupling and edge-induced spectral characteristics of nanoscale semiconductor materials, laying a foundation for in-depth understanding of its photoelectric characteristics and related devices.

Prof. Chen Jinquan from East China Normal University gave a report titled “Application of Ultrafast Chiral Spectroscopy in Chemical and Biological Systems”. He introduced the femtosecond time-resolved circular dichroic absorption spectroscopy (fs-TRCD) and femtosecond-nanosecond circular polarization emission spectroscopy (TR-CPL) technologies independently developed by his research group, which realized the precise measurement of the excited state chirality generation and transfer process of dye molecules, rotaxane molecules and their derivative systems.

Wu Kaifeng, a researcher from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, gave a report titled “Quantum Dot Ultrafast Photophysics and Photochemistry”. Wu’s research group observed the exciton spin quantum beat frequency at the ensemble level in colloidal quantum dots, demonstrating the temperature-adjustable exciton fine energy level splitting and coherent dynamics. By means of ultrafine interfacial electron transfer, they prepared long-lived hole spin states at room temperature. Based on the optical Stark effect, he was the first to realize the coherent manipulation of the spin of quantum dots at room temperature, directly observed the spin quantum coherence characteristics of the hybrid free radical pairs of quantum dots and organic molecules, and realized the efficient magnetic field regulation of the three-wire photochemical reaction.

After the reports, Liu Xinfeng, Chen Jinquan and Wu Kaifeng discussed relevant issues with the teachers and students present, and took a photo with the teachers.