Date of Completion

6-12-2014

Embargo Period

6-10-2014

Keywords

Aerogels, Transparent Conducting Oxide, Dye-Sensitized Solar Cells

Major Advisor

Alexander G. Agrios

Co-Major Advisor

Timothy Vadas

Associate Advisor

Ali Gokirmak

Associate Advisor

Steven L. Suib

Associate Advisor

Brian Willis

Field of Study

Environmental Engineering

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

Aerogels are attractive structures due to their high surface area, high porosity and particle interconnectivity, which are desirable properties for many device applications. They can be made by a facile sol-gel synthesis from low-cost metal salts to produce monolithic gels. These are dried supercritically to avoid the collapse of the structure that occurs with surface tension at the liquid-gas interface. SnO2 is a n-type, wide bandgap semiconductor. Doped SnO2 materials can exhibit transparency throughout the visible range of the solar spectrum and low electrical resistivity. They are commonly used as transparent conducting electrodes (TCEs) for a wide array of applications including solar cell fabrication. Here, doped-SnO2 aerogels are synthesized as bulk and thin film monoliths, the latter serving as porous electron collectors in dye-sensitized solar cells (DSCs). This thesis is an in-depth study of the effects of dopants, namely fluorine and antimony, in the properties of SnO2 aerogels. First, the use of fluorine and antimony is investigated to understand the effect of these dopants on the physical and optoelectronic properties of the SnO2 materials. Doped aerogels are then used as thin films and coated with conformal layers of TiO2 to fabricate DSCs. Solar cell characterization, including performance analysis and electron kinetics in the device, is conducted to understand the advantages of this system compared to the traditional TiO2 DSCs.

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