题目：Dye-Sensitized Lanthanide-Doped Core/Shell Inorganic Nanocrystals in the Near Infrared Range
时间：2017年6月29日（周四）下午3点
地点：光电工程学院南区1118会议室
报告人：Prof.Guanying Chen(Harbin Institute of Technology)
报告摘要：Lanthanide-doped upconverting and downshifting nanoparticles hold promises for applications ranging from solar cells to bioimaging. However, their emission brightness and excitation wavelength range are limited by the weak and narrowband absorption of the doped lanthanide ions, creating a long-standing obstacle for a comprehensive range of technolgical applications. This limitation primarly associates with the parity-forbidden nature of the 4f-4f electronic transitions of trivalent lanthanide ions. Here, I present our recent progress on exploiting hybrid inorganic-organic systems to address this problem, which consist of an epitaxial core/shell inorganic nanocrystal and near infrared (NIR) dyes anchored on the core/shell nanocrystal surface. We employed the dye attena effect to broadly and strongly harvest NIR light first, and then directed the harvested energy to migrate across both the organic-inorganic (dye/shell) interface and the inorganic core/shell interface, and finally to activate the emitting lanthanide ions positioned the inorganic core in a designated way. This strategy allows us to yield unprecedented three-photon upconversion (visible by naked eye as blue light) of an incoherent infrared light excitation with a power density comparable to that of solar irradiation at the Earth surface, and to produce tunable narrow-band downshifting photoluminescence for deep tissue bioimaging in the second biological window.
简历：Dr. Guanying Chen received his B.S. and Ph.D. degrees in applied physics in 2004 and in optics in 2009, respectively, from Harbin Institute of Technology (HIT), China. After obtaining his PhD, he became an assistant professor in HIT in 2009, and was promoted to an associate and full professor in 2013 and 2014 respectively. During the period of 2009-2011, he did his postdoc at SUNY Buffalo. Since 2012, he hold a joint position as a research associate professor at the Institute for Lasers, Photonics and Biophotonics (ILPB), SUNY Buffalo. He has published more than 80 SCI papers in Chem Rev (2 papers), Chem Soc Rev (3), Acc Chem Res (1), JACS (2), Adv Mater (1), and ACS Nano (4), etc. His publications has been cited by others about 5100 times (Google Scholar). His main interest lies in the development of upconversion nanoparticles for a broad spectrum of biophotonic and photonic applications.
