Sept. 26, 2011

U-M's Stephen R. Forrest analyzes the efficiency, reliability, and potential of organic photovoltaic technology for widespread commercial application.

ANN ARBOR, Mich. ­– Imagine paints that can collect solar energy to power a car or living room windows that harvest the sun’s rays to generate electricity for a home.

Through a new $1.5 million grant from the Department of Energy’s SunShot Initiative, Stephen R. Forrest, the University of Michigan’s Vice President for Research, moves such possibilities closer to reality by analyzing the efficiency, reliability, and potential of organic photovoltaic technology for widespread commercial application. Forrest’s work examines the promise of capturing and distributing the power of the sun via materials that are lighter, more pliable and less expensive than current silicon-based systems.

“The type of organic materials we use are not very different from the inks in an inkjet printer or the dyes used in clothing,” he said. “Some are very good semiconductors. In principle, they can be put down very cheaply on plastic films, metal foils and other flexible substrates.”

The research is based on proprietary small molecule systems developed by Forrest with Global Photonic Energy Corporation, where he serves as a research partner, that incorporate semi-transparent, organic materials stacked in a tandem architecture. This arrangement maximizes the ability to capture photons – the bundles of sunlight energy ­– passing through the cells. The tandem structure, Forrest estimates, achieves about 30 percent more efficiency than single-cell architecture.

While Forrest said the technology remains “next generation,” its potential is far-reaching.

“Commodity electricity generation is a pretty long step from here,” he said.  “That requires a very proven and mature technology. Still there are a lot of interesting niches that could be exploited before that — coatings on windows and coatings on car surfaces, for example. From there you could move into rooftop residential and from there to commodity generation solar farms.”

The new Department of Energy grant was awarded earlier this month in the SunShot Initiative’s Transformational PV Science and Technology: Next Generation Photovoltaics II category.  The award follows an initial round of research funding for Forrest in the Next Generation Photovoltaics category.

The Department of Energy’s SunShot Initiative aims to make solar energy cost competitive with other forms of energy by the end of the decade.  According to the DoE, a reduction in the installed cost of solar energy systems by about 75 percent will drive the adoption of solar technology and strengthen the nation’s global stature in clean energy development and use.

Contact: Paul Gargaro, Michigan Memorial Phoenix Energy Institute, 734-615-5678, pgargaro@umich.edu, or David Lampe, Office of the Vice President for Research, 734-647-7768, drlampe@umich.edu.