Day 3 :
University of Waterloo, Canada
Keynote: Generating efficient and tunable white light using electronically coupled nanocrystal and molecular building blocks
Time : 09:00-09:25
Pavle Radovanovic received his Ph.D. degree from the University of Washington, Seattle. Following his postdoctoral appointment at Harvard University, and started his independent research career at the University of Waterloo in 2006. At Waterloo he initiated a new research program in physical-inorganic chemistry focusing on the design, synthesis, and fundamental physical and chemical properties of multifunctional low-dimensional materials. His work has been recognized by number of honors and awards, including Canada Research Chair (NSERC), Early Researcher Award (Ontario Ministry of Research and Innovation), Mobility Award (French Ministry of Foreign Affairs), and CNC-IUPAC Award.
Native defects, including lattice site vacancies and interstitials, are a source of many useful and often unexpected properties in solid-state materials. In this talk I will first present our recent results on defect-based photoluminescence properties of colloidal wide band gap metal oxide nanocrystals (Ga2O3 and ZnO), and the effect of nanocrystal size on the photoluminescence energy, efficiency, and dynamics. Coupling of the native defects with selected molecular fluorophores bound to nanocrystal surfaces via energy transfer allows for the emergence of complex optical properties. One of the examples that will be discussed is generation of white light that can be tuned based on the nanocrystal size and the concentration of luminescent adsorbates on nanocrystal surfaces. The ability to modify nanocrystal surfaces allows for further optimization of the stability and functionality of the resulting nanoconjugates. The extension of these results to composite films consisting of photoluminescent nanocrystal energy donors and acceptors represents a path to all-inorganic rare earth element-free white-emitting phosphors. The implications of this work for high-efficiency photonic devices, such as white light emitting diodes, will also be discussed.
Harbin Institute of Technology, Shenzhen, China
Time : 09:25-09:50
Ho-Kei Chan is an Associate Professor at the Harbin Institute of Technology, Shenzhen, China. After completing his undergraduate degree at the Hong Kong Polytechnic University, Chan moved to the University of Manchester for a PhD in physics. This was followed by post-doctoral research in the Hong Kong Baptist University, Trinity College Dublin, and then the University of Nottingham. Chan has published a variety of scientific articles in the fields of statistical, nonlinear, and soft matter physics, most notably his work on a template-based method of sequential deposition for generating a wide range of densest columnar packings of spheres.
A stack of oranges on display at a grocery store represents a solution to a centuries-old problem: how can we pack identical spheres as densely as possible in an open space? An endless variety of such packing problems exists, including the packing of spheres, spheroids, rods, deformable bubbles, and many other shapes, where one may also consider packing them as densely as possible into a confined geometry. Powerful computer techniques have opened up new avenues for solving packing problems. With the discovery of some optimal mathematical structures, results from computer simulations have not only helped to verify or disprove some very old conjectures, but have also led to new insights into structures of matter and new inspirations for the design and fabrication of materials.