Advanced Materials Deposition for Semiconductor Nanostructures Using Supercritical Fluids
Abstract
Supercritical fluid carbon dioxide provides an attractive medium for depositing materials in small structures with high aspect ratios and poorly wettable substrates due to the fact that it is able to dissolve solutes like a liquid and transport dissolved materials like a gas. Metal and metal sulfide nanoparticles of controllable size can be synthesized in supercritical fluid carbon dioxide using water-in-CO2 microemulsion as template. Continuous tuning the size of metallic nanoparticles and metal sulfide nanoparticles with diameters from less than 2 nm to over 10 nm can be achieved by varying the density of the fluid phase in the synthetic process. The synthesized nanoparticles are stabilized in the fluid phase using an alkylthiol compound. Deposition of the stabilized metal nanoparticles in the fluid phase forming self-assembled arrays has been demonstrated. Supercritical fluid deposition of metals on surfaces of carbon nanotubes has also been studied. Metal nanoparticles of narrow size distributions can be uniformly attached to carbon nanotube surfaces using this method. The carbon nanotube-supported platinum group metal nanoparticles show remarkably high activities for catalyzing chemical and electrochemical reactions. Examples of utilizing the carbon nanotube-nanoparticle composite materials as catalysts for chemical reactions, fuel cells and sensor applications are given.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2007
- Accession Number
- ADA466115
Entities
People
- Chien M. Wai
Organizations
- University of Idaho