2008

Printed Flexible Solar Cells Provide Embedded Renewable Power

In the effort to produce inexpensive, easily manufactured sources of sustainable, renewable power, solar cells continue to be a major focus — particularly flexible solar cells that can be applied directly to surfaces. Flexible solar cells are nothing new, but the methods by which they are made have progressed significantly in recent years.

One company, Konarka Technologies of Lowell, MA, recently announced that they had demonstrated the ability to manufacture solar cells by inkjet printing. The company’s Power Plastic® solar cell technology — which is the result of a project originally funded by the U.S. military — uses a wider range of the light spectrum than conventional solar cells. All visible light sources — not just sunlight — can be used to generate power. It can be used virtually anywhere there is a light source and a battery.

ImageDr. Christoph Brabec is Chief Technology Officer at Konarka, and previously worked in polymer photovoltaics at Siemens. As a polymer scientist, he helped develop the nanomaterials that are the basis of Power Plastic. He holds 30 patents. NASA Tech Briefs talked with Dr. Brabec about the company’s technology, and the potential impact their novel inkjet printing technique could have on producing low-cost flexible solar cells for a myriad of commercial and industrial applications.

NASA Tech Briefs: How did the U.S. military project lead to the founding of Konarka in 2000?

Dr. Christoph Brabec: In 2000, the U.S. Army provided funding for an elite team of scientists under the coordination of the Army’s Natick, Massachusetts Laboratory to develop advanced photovoltaic technology for soldiers. The team achieved a remarkable breakthrough.

They discovered a new technology to facilitate materials processing at relatively low temperatures. This discovery enabled, for the first time, the use of a wide variety of low-cost polymers as the top and bottom surfaces of the photovoltaic cell. It also enabled the photovoltaic cells to be manufactured at a much higher speed. The resulting plastic- based photovoltaic cells are efficient across a much broader spectrum of light than traditional solar cells, allowing them to be useful indoors as well as outdoors.

This breakthrough led to the founding of Konarka in July 2001. The revolutionary chemical process and the roll-toroll manufacturing process led to several pending patents and issued patents.

Since the founding of the company, Konarka has continued to refine the manufacturing process; increase the efficiency of its photovoltaic products; acquire key intellectual property from around the world; develop collaborations with leading research agencies, universities, and global energy companies; and develop products that provide a source of renewable power in a variety of form factors for commercial, industrial, government, and consumer applications around the world.