31st October 2008 – 12:00
Speaker:
Dr. Lionel Vayssieres
Location:
Aula Seminari Dip. Sc. e Tec. Chimiche, Campus
Abstract:
The demand of novel functional materials has become the major challenge scientists face to answer crucial contemporary issues such as alternative energy sources, novel sensors for a safer and cleaner environment and for health (e.g. early detection of cancer and regenerative therapies). For instance, one of the promising alternatives for the transition of energy resource from its fossil fuel-based beginning to a clean and renewable technology relies on the widespread implementation of solar-related energy systems, however the high cost of energy production and low-energy of currently used material combinations pose an intrinsic limitation. In this context, revolutionary materials development is required to achieve the necessary dramatic increases in power generation and conversion efficiency. The need of low cost purpose-built, functional materials with optimized geometry, orientation, and aspect ratio combined with inexpensive large scale manufacturing methods will play a decisive role in the success of solar related energy source. However, fabricating and manufacturing large area of such functional materials is a daunting challenge. Novel smarter and cheaper fabrication techniques and, just as important, better fundamental knowledge and comprehensive understanding of materials and their syntheses as well as their properties using nanoscale phenomena such as quantum confinements to create multi-functional structures and devices is the key to success. R&D exploiting Nanoscience and Nanotechnology has the greatest potential to reach such challenging goals.
Such ideas will be demonstrated by the low-cost design and fabrication of 3-D crystalline arrays of metal oxide quantum dots and rods based structures and devices with controlled orientations, size and shape onto various substrates designed at nano-, meso-, and micro-scale by aqueous low-temperature chemical growth. In addition, in-depth characterization of their electronic structure at synchrotron radiation facilities and their application for solar hydrogen generation, photovoltaics, magnetic and gas sensor devices will be presented.