Dissertation Title:
“ UV-Ozone Oxide Treatments for High-Efficiency Silicon Photovoltaic Devices ”
Abstract:
Fabrication of solar cells with higher efficiency, simpler processes and lower cost is largely perceived as the ultimate goal for photovoltaic research. To reach such a goal each step needs to be refined and optimized. In this dissertation, a UV-ozone treatment is proposed as a simple and versatile process that can be applied to multiple fabrication steps for improvement. The UV-ozone cleaning method provides comparable surface cleaning quality to more expensive and hazardous industrial standard RCA clean with less chemical used. A good passivation quality was achieved on both n-type and p-type silicon wafer by a silicon oxide/aluminum oxide passivation stack, formed by UV-ozone treatment and ALD. Creating a thin layer of silicon oxide on the silicon wafer surface before depositing the aluminum contact form a metal-insulator-semiconductor (MIS) contact structure, showing low contact resistance for both n-type and p-type wafers. Device performance simulation was performed by Quokka and Sunsolve using experimental results. The simulation results shown promising power conversion efficiency and indicated contact resistance as the key factor in reaching higher efficiency.
Committee in Charge:
Dr. Winston V. Schoenfeld, Chair
Dr. C. Kyle Renshaw
Dr. Peter J. Delfyett
Dr. Kristopher Davis
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