Using Plastics to Make Solar Cells More Cost-Effective

Tuesday, August 11 2009

Scientists are striving to develop organic solar cells that can be produced as easily and inexpensively as thin films. A major obstacle is coaxing these carbon-based materials to reliably form the proper structure at the nanoscale. The goal is to develop cells made from low-cost plastics that will transform at least 10 percent of sunlight into electricity.

A team headed by David Ginger, associate professor of Chemistry at University of Washington, uses an atomic force microscope to quickly determine whether certain polymers are ever likely to reach the 10 percent efficiency threshold.

Most researchers make plastic solar cells by blending two materials together in a thin film, then baking them to improve their performance. In the process, bubbles and channels form much as they would in a cake batter. The bubbles and channels affect how well the cell converts light into electricity, and how much of the electric current actually gets to the wires leading out of the cell.

The exact structure of the bubbles and channels is critical to the solar cell's performance, but the relationship between baking time, bubble size, channel connectivity, and efficiency has been difficult to understand.