Reported by Stella Lee

Thin film solar technologies based on organic photoactive materials see growing demand. Using toxic materials to generate green energy doesn’t make sense. The growing demand for sustainable sources of energy and the increasing interest in green material technologies have triggered a huge attention to Organic Photovoltaics (OPV). This type of solar cells offers new opportunities of application and is also expected to enlarge the usage of the solar energy in our life.

Shinji Kawahara, Director of Business Development for Konarka, says that portable, safe electricity is always at hand with flexible organic PV modules. “To expand the use of solar technology to a world of new applications, Konarka’s organic photovoltaic technology is transforming the way we generate power,” says Kawahara.

OPV is different from other thin-film technologies in terms of environmental friendliness. It is made out of polymers, which are non-toxic. “OPV is the greenest PV technology in the marketplace. OPV is formed from organic components and is free of any toxic or hazardous materials or substances. OPV ranks the highest in every category of green technology from the amount of energy manufacturing, energy-related costs, carbon footprint, to energy payback time,” says Kawahara.

OPV can be bent with a diameter of no less than five centimeters, also color variability for reds, greens, and blues will be available in the future. OPV offers several colors of semi-transparent films and features an impressive positive temperature coefficient and works well under a wide range of temperatures. OPV is also capable of generating electrical power under low-light conditions for both indoors and outdoors, according to Kawahara.

Konarka started OPV business early 2009. Initially, they developed core materials for end-user products such as portable chargers, so-called solar bags, and shading elements where consumers can recharge portable electronic devices. Today Konarka is focused on manufacturing organic photovoltaics. “Our target customers are facade, glass, membrane, and other building materials suppliers as well as system integrators and dealers. Also general contractors, technical engineering firms, and architects as well,”  says Kawahara.

Konarka’s materials are sensitive to low light because they have their own specialized technologies. The sensitivity depends on the characteristics of semiconducting polymers and configuration of bulk-hetero junction, explains Kawahara.

“OPV is a very realistic product because OPV features an impressive positive temperature coefficient and this characteristic shows that OPV generates electrical power at higher temperatures. OPV also can perform from dawn to dusk by its low-light sensibility. As a result, energy accumulation of OPV, in comparison with competitive products, such as amorphous silicon, crystal silicon, and CIGS technologies, is much higher at 20 to 35% by using panels equating to 5W,” he says.

A large-scale New Energy and Industrial Technology Development Organization (NEDO) project in Japan is encouraging the PV industry in the country, but, unfortunately, NEDO has focused on conventional solar cells yet.

However, Kawahara’s expectations for the development of the OPV market in Japan this year are still positive. “We expect to develop BIPV applications for each building material segment by working with appropriate partners in Japan as well as in Asia especially using semi-transparent products,” says Kawahara.

Then, what were the obstacles that Konarka had to overcome in order to mass-produce and commercialize OPV applications? “Stable production at our main factory in Miami was very important factor for mass-produce. Our cell efficiency is 8.3% certified by NREL. We have achieved the production by a roll-to-roll process in order to produce stable OPV in terms of performance and quality. Conversably, other thin-film makers are using vapor deposition process,” Kwahara says.

Stella Lee is Editor of InterPV. Send your comments to pved1@infothe.com.