Speaker: Jeffrey W. Elam, Argonne
Date & Time: October 5, 2006 - 11:00am
Location: Room 260, Wright-Rieman Chemistry
Atomic Layer Deposition for the Surface Modification of Nanoporous Materials
Laboratory for Surface Modification
Jeffrey W. Elam, Argonne
11am, Room 260, Wright-Rieman Chemistry
Atomic layer deposition (ALD) is a powerful method for applying precise, conformal coatings over nanoporous materials. ALD utilizes a binary reaction sequence of self-saturating chemical reactions between gaseous precursor molecules and a solid surface to deposit films in a monolayer-by-monolayer fashion. In this presentation, I will describe two new ALD processes that we have developed for applications in energy production and utilization. The advantage of these new processes is that they allow the conformal coating of nanoporous substrates including very high aspect ratio anodic aluminum oxide membranes and ultra-low density silica aerogels. The first process is the ALD of indium oxide transparent conducting oxide (TCO) films using cyclopentadienyl indium and ozone. This technique will enable the functionalization of porous materials with In-based TCO films such as indium-tin oxide (ITO) for the fabrication of novel photovoltaic devices. Next, I will describe the ALD of yttria-stabilized zirconia (YSZ) thin films using cyclopentadienyl precursors and water. Yttria-stabilized zirconia (YSZ) is the most commonly used solid electrolyte material for solid oxide fuel cells (SOFC) and also for hydrogen production through steam electrolysis. For these ALD processes, we use in-situ quartz crystal microbalance and mass spectrometric measurements to understand the surface chemistry controlling the layer-by-layer growth, and we employ a range of ex-situ analyses to examine and characterize the deposited films.