应实验室邀请，美国俄亥俄大学Alexander Govorov教授将于9月26日（星期二）上午10：00-11:30，在能动学院北二楼11楼会议室举办学术讲座，请实验室师生积极参加学习交流。
Title: Theoretical studies of optical and energy-related phenomena in hybrid nanostructures
Abstract: Different materials such as semiconductors, metals, biomolecules and polymers are used to fabricate hybrid nanostructures. Semiconductor quantum dots and wires are good optical absorbers and excitations in these nanocrystals (excitons) are long-lived and can be efficiently transferred via the Coulomb interaction. Metal nanocrystals exhibit strong plasmon resonances and have the ability to scatter light very efficiently. Bio-molecules and polymers allow us to create assemblies with a precise positioning of optically-active nanocrystals. One impressive technique to assemble nanoscale objects is called the DNA-origami approach. This talk will discuss a few key energy-related phenomena that appear in hybrid nanostructures. (1) Using plasmonic nanostructures, one can strongly enhance optical generation of heat and also confine high photo-temperatures in small volumes [1,2]. (2) Nanostructures with plasmonic hot spots efficiently generate energetic (hot) electrons, which can be used for photochemistry and photodetection [3,4]. (3) Colloidal nanocrystal assemblies with plasmon resonances allow us to strongly enhance the chiral optical response (circular dichroism) of biomolecules [5,6]. (4) Using DNA-assembled nanoparticle arrays made of different metals, one can transfer plasmonic signals coherently and with small losses [7].
References :
[1] A. O. Govorov and H. Richardson, Nano Today 2, 20 (2007).
[2] C. Jack, et al., Nat. Commun. 7,10946 (2016).
[3] A.O. Govorov, H. Zhang, H.V. Demir and Y. K. Gun’ko, Nano Today 9, 85 (2014).
[4] H. Harutyunyan, et al., Nature Nanotech. 10, 770 (2015).
[5] A. O. Govorov, et al., Nano Letters 10, 1374–1382 (2010).
[6] A. Kuzyk, et al., Nature 483, 311 (2012).
[7] E.-M. Roller, et al., Nature Physics , accepted; arXiv:1701.04672.
Biography:
Alexander O. Govorov, Distinguished Professor of Physics at Ohio University, USA; Fellow of the American Physical Society; total number of papers > 205, h-index=58 (Google Scholar). Dr. Govorov is an expert in theoretical physics of nanostructures and nanomaterials. His research interests include the optical and electronic properties of nanoscale structures like quantum dots and rings, plasmonic nanocrystals, nanowires, metamaterials, and bio-assemblies. Dr. Govorov’s theoretical predictions motivated experiments in many research labs worldwide. Dr. Govorov is a recipient of the Friedrich Wilhelm Bessel Research Award from the A. v. Humboldt Foundation (Germany), the Ikerbasque Fellow Award (Spain), the Walton Visitor Award (Ireland), the 2014 Jacques-Beaulieu Excellence Research Chair Award (Canada) and the Chang Jiang (Yangtze River) Chair Professorship (China).
