|Jul. 09, 2014, 16:30 - 18:00|
|Institute of |
|Talk by Prof. Helmut Baumgart|
Nano-porous templates have played an important role in the quest to fabricate 1-dimensional nano-structured materials, such as nano-wires, nano-fibers, nano-tubes or nano-rods and novel device architectures. Porous anodic aluminum oxide (AAO) offers precise control over the dimensions of the synthesized nano-tubular pore structure, which includes control of the pore diameter, the pore wall thickness and the aspect ratio. In this presentation, we expand the potential applications of generic porous templates by utilizing atomic layer deposition (ALD) to create far more complex nested multiple-walled nanostructures within any porous templates. Atomic layer deposition is a thin film growth technology based on a sequence of two self-limiting reactions between gaseous precursor molecules and a solid surface to deposit films in a layer-by layer with atomic resolution. Since gas phase reactants are utilized, conformal coatings can be achieved with very high aspect ratio geometries on three-dimensional (3D) porous structures. Such template guided, conformal depositions by ALD can produce concentric nested multilayered nanotubes and thus enable the fabrication of multilayered nanotube architectures inside the nanopore templates. The nanoporous Si template approach lends itself to the development of bottom-up nanofabrication methodologies for solar cell architectures used as power conversion components composed of highly-ordered, interdigitated anode and cathode nanoelectrodes. Such a technology is of interest to bulk heterojunction (BHJ) organic solar cells for next generation photovoltaics.
A layer-by-layer synthesis founded upon a conformal surface has been developed to decisively control three-dimensional parameters such as height, thickness and spacing between nanostructures with high resolution over large, planar areas. This technology will not only allows for tailorable and customized nanoelectrodes’ geometries but also yield far greater functionalities in terms of tunability of 3D parameters and compositions of nanostructures.
In another application of template guided technology we succeeded to utilize the template as porous nano-membrane to build a novel two terminal electro-osmotic pump for portable drug delivery applications to deliver insulin for example. Our proposed electro-osmotic device relies on our ability to functionalize the inner walls of the nano-pores in order to modulate the zeta potential.
|This event is part of the eventgroup INT Talks|
Prof. Helmut Baumgart
Old Dominion University, Norfolk, Virginia
Department of Electrical and Computer Engineering
Prof. Dr.-Ing. Horst Hahn
Institute of Nanotechnology (INT)
Karlsruhe Institute of Technology (KIT)
Mail:horst hahn∂kit edu