Shola Marie Wylie

October 17, 2014

Organic Solar Cells: Finding the Origin of the Intrinsic Electric Field

With the threat of global warming looming and the cost of fossil fuels rising, the search for clean and renewable energy sources has intensified. Recently, organic photovoltaic devices have sparked interest in the scientific and commercial communities for offering many advantages including flexibility, affordability, and versatility. While they offer these advantages, their power conversion efficiency is too low to be competitive in the commercial markets. Many of the models that describe the efficiency of organic devices are based on the existence of a built-in electric field, but the origin of this built-in electric field is not well known. The research I conducted this summer at Mount Holyoke College worked on answering this question by using a novel technique called electromodulation imaging. This technique allowed me to take high-resolution photographs of the device reflection while the devices were switched on and off. Using these photographs, I can see the change in reflectivity of the device, which can change due to an electric field, charge concentration, or temperature. This research is still in progress and upon completion will be part of my senior thesis.