Exploratory Efforts 2007
Plasma Activated Fuel Cells
Nanowire-Nanocrystal Multiexciton Solar Cells
Yi Cui, Materials Science and Engineering, Stanford University
This project explores a novel photovoltaic cell architecture using a network of PbSe nanowires combined with PbS nanocrystals. The aim of this project is to use the proposed structure to achieve both high photon absorption through impact ionization processes in the nanocrystals, and efficient charge transport through both the nanowire network and the nanocrystal arrays filling the void space in the nanowire scaffold. This concept is a new approach to the realization of high-efficiency thin film photovoltaics, and will require the exploration of fundamental questions, many of which will also benefit other innovative thin film technologies.
Increasing Carbon Storage Within Soils by Controlling Key Microbial Respiration Processes
Scott Fendorf, Environmental Earth System Science, Stanford University; Shawn Benner, Department of Geosciences, Boise State University
Integrating carbon sequestration objectives into traditional agricultural practices has the potential to provide dramatic short-term offsets in carbon emission. Managed wetlands, rice paddies in particular, represent a promising distributed carbon sink; if the average carbon content within the upper meter were increased by a few percent, the total annual carbon dioxide release from the burning of fossil fuels could be offset. It is conceivable that we could double the carbon content over a ten-year period, reaching an average total soil carbon content of 4-8%. This project will test the hypothesis that microbial methanogenesis can be minimized while simultaneously limiting carbon mineralization rates through control of water levels, periods of inundation, rates of both flooding and draining, and specific iron(III) mineral availability within rice paddies. The objectives of the exploratory study are: 1. to examine current organic carbon and iron mineral phase contents within existing wetlands under different historic management practices; and 2. to conduct a pilot study wherein the operative microbial metabolisms are controlled to limit carbon mineralization rates (relative to aerobic rates) while restricting methane production.
Feasibility of a Novel Photoelectrochemical Conversion Device
Nanostructured ZnO as a Solution-Processable Transparent Electrode Material for Low-Cost Photovoltaics
Alberto Salleo, Materials Science and Engineering, Stanford University
This study explores innovative approaches for using zinc-based oxide materials as transparent conductive films in photovoltaic devices. The proposed strategy consists of depositing a planar network of doped ZnO nanowires from solution and annealing it by laser to form a continuous film. This approach promises better conductivity and transparency properties than in unannealed nanowire networks, in addition to the advantages associated with solution processing. Laser annealing of highly-doped ZnO nanowires is a novel technique that will be investigated for the first time in this project.
High Voltage Alloys for Lithium Battery Cathodes
Robert Huggins, Materials and Science Engineering, Stanford University
This exploratory program researches the feasibility of new cathode materials to improve battery performance in vehicles and other weight-sensitive applications. Unlike typical transition metal oxide materials currently used in lithium battery cathodes, these high voltage metal and metal-metalloid alloys will have a lower weight and thus improve the specific energy of batteries. The research will explore the feasibility of making lithium alloy cathodes using various chemical and electrochemical methods. It is anticipated that preliminary results from this work will reveal whether there is a convincing pathway for battery cathode materials of the type investigated in this study to have the potential for impact at scale.