报告人：Prof.Yujun Shi （Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4）
标题：Fabrication of Au, Pt, and AuPt Nanoparticle Arrays on Patterned Substrates by Pulsed Laser-induced Dewetting
Gold (Au) and platinum (Pt) nanoparticle (NP) arrays have found many applications in catalysis, sensors, magnetic storage devices and nanoelectronics. The fabrication of Au and Pt NP arrays is most commonly accomplished by lithography-based nanopatterning. However, this approach is expensive and time conusming. Pulsed laser-induced dewetting (PLiD), on the other hand, provides an alternative, simple and efficient method for the production of metallic NPs with controlled spacing and order. In this talk, I will present our recent work on the fabrication of Au and Pt NP arrays via PLiD of single-layer metallic films on nanopatterned Ta substrates without the need for lithography. Our work has shown that PLiD can be used to produced NP arrays of both low-melting-point and high-melting-point metals, providing a powerful alternative to thermal dewetting. In addition, quantitative evidence has been provided to show that PLiD of Au and Pt follows spinodal dewetting mechanism. Pt-Au bimetallic NP arrays can also be produced via PLiD of bilayer thin films on template Ta substrates. The effect of laser parameters, substrate and sputtering sequence on the NP size, long-range order and composition will be discussed.
Dr. Yujun Shi is Professor and Associate Head (Research) in the Department of Chemistry at the University of Calgary in Canada. She received her BSc and MSc in Chemistry from Soochow University, and her PhD from the University of Western Ontario (now Western University) in Canada. After her postdoctoral work in the Steacie Institute for Molecular Sciences at the National Research Council of Canada with an NSERC Visiting Fellowship, Dr. Shi joined the Department of Chemistry at University of Calgary as an Assistant Professor in 2003. Her research focuses on application of laser dewetting methods for metal nanoparticle formation, development of laser analytical techniques, and understanding the chemical vapor deposition at a molecular level. Dr. Shi has published 2 book chapters, over 70 papers in peer-reviewed journals, and 2 US patents.