Summer 2010 Intern Project- Jeffrey Georgette
NANOSTRUCTURED INORGANIC/ORGANIC HYBRID SOLAR CELLS
UC Santa Barbara
Mentor: Syed Mubeen Jawahar
Faculty Advisor: Martin Moskovits
Over the last few decades, there have been consistent efforts in developing new, reliable, cheap and environmental friendly energy sources. Direct conversion of solar energy to electricity by photovoltaic cells is a good solution. Currently, poly-crystalline silicon photovoltaic cells on the market have efficiencies around 20%, and their cost is $3 per watt of energy generated. This cost has to be reduced to compete with other energy systems. Tremendous research has been devoted to develop new material processing and device architectures to fabricate solar cells in a cheap and reliable fashion, yet providing acceptable efficiencies.
The goal of this project is to integrate the inexpensive processing properties of semiconducting organic polymers with the superior optical, electrical, and carrier transport properties of inorganic semiconductors and fabricate a hybrid solar cell with improved cell efficiencies and low production cost. The strategy employed here is to pattern organic semiconductors around inorganic semiconductor nanowires fabricated using nanoporous templates. For example, ultra high density arrays of CdSe nanowires with diameters of 50 – 75 nm were fabricated on indium-tin oxide coated glasses (ITO) by electrodeposition, inside highly ordered nanoporous templates prepared by anodizing aluminum. After removal of these templates, freestanding inorganic nanowires are obtained. These arrays of inorganic semiconductor nanowires could be used as n-type materials in photovoltaics, and because of their vertical geometry a p-type organic semiconducting polymer (P3HT in this case) can be easily spun on into the array. Finally, solar cells fabricated in such fashion are characterized by I-V and photocurrent measurements.