Santa Clara University

"Organic Solar Cells: Clean and Inexpensive Solar Power"

Emilee Sena; Devin Wesenberg

Faculty Mentor: Richard Barber

Solar cells are a sustainable, clean approach to converting solar energy into an electric current. Their use results in a minimal environmental impact: they do not release air or water pollutants, nor greenhouse gases. Furthermore, solar cells can be used in remote areas. This makes them globally accessible sources of energy. Currently the most widely- used solar cell, or photovoltaics (PVs), are inorganic semiconductor-based PVs, which have many shortcomings. They are expensive, difficult to manufacture, fragile, and the panels are rigid and must be placed on very flat surfaces that face the sun. In contrast, organic photovoltaics (OPVs), are made from organic compounds and cost little in comparison to inorganic PVs. OPVs are easily manufactured on a large scale through roll-to-roll processing. They are lightweight and flexible. As a result, these panels are easily transportable and can be placed on a variety of surfaces for more versatile use. However, these materials also have limitations which reduce the likelihood of replacing the current technology: they have lower efficiency and they degrade over time. Our primary objective is to understand the degradation mechanisms in these materials. We apply a systematic approach to discover how various aspects of device preparation and chemical composition affect degradation. By doing this basic research, we hope to clarify the process of degradation in order to contribute to the development of cheaper solar power.
Research Update:
In March Emilee presented a talk:Emilee Sena, Justin Peel, Shreya Nathan, Devin Wesenberg, Marianne Wallis, Thorsteinn Adalsteinsson, Brian McNelis and Richard Barber, "UV-vis and Transport Characterization of Degradation in Polymer Blend Photovoltaics," (contributed) presented by Sena at the March Meeting of the American Physical Society, Dallas, 2011.This talk won recognition as an outstanding undergraduate presentation and was supported in part by the first grant. The March Meeting is the largest US physics conference.

In September Rich submitted the manuscript:
Emilee L. Sena, Justin H. Peel, Devin Wesenberg, Shreya Nathan,
Marianne Wallis, Maxwell J. Giammona, Thorsteinn Adalsteinsson, Brian
J. McNelis, and Richard P. Barber, Jr., "Transport and Spectroscopic
Studies of the Effects of Fullerene Structure on the Efficiency and
Lifetime of Polythiophene-based Solar Cells," to Solar
Energy Materials & Solar Cells for review. The manuscript was supported in part by both grants. Solar
Energy Materials & Solar Cells is an international peer-reviewed
journal with a fairly high impact factor.