A Limoges, France-based leader in the field of offset and screenprinting, Disatech has developed a well-deserved reputation for R&D and customer service. When the company is asked by a client if it can take on a tough project, Disatech figures out a way to accomplish the job.

Naturally, when an important client asked Disatech if it thought it could produce printed flexible solar cells, the printer decided to give it a try. As a result, DisaSolar, Disatech’s organic photovoltaic (OPV) subsidiary came into being, and the company has been successfully developing and manufacturing OPV cells ever since.

“In 2008, one of our major clients asked us if we had the ability to manufacture flexible solar cells for the tops of trains,” said Stephane Poughon, DisaSolar CEO. “We didn’t know anything about photovoltaics, but when a client asks you if you can do something, you’d better say yes. Within two years, we were able to do this.

“Now we have developed a really strong knowledge of organic photovoltaics,” Poughon added. “We then decided it might be a good opportunity to start our subsidiary.”

For a variety of reasons, DisaSolar decided to branch into OPV. OPV cells are versatile, as they are flexible, lightweight and unbreakable. They can be custom-made in any shape, size or color, and can also be transparent. OPV is also more eco-friendly, due to lower energy consumption and the usage of non-toxic materials that are 100% recyclable.

OPV cells offer numerous performance advantages as well. These cells perform well in artificial lighting and low lighting, both indoors and outdoors. OPV cells offer a positive temperature coefficient, as the higher the temperature, the better the OPV cells perform. By contrast, efficiencies of traditional PV cells decline as temperatures rise.

Cost is also a benefit for OPV, as abundant materials, lower introduction investment and low temperature manufacturing costs make OPV competitive in terms of pricing. Disa Solar opted to use inkjet printing, which is an additive process. All the active materials (semiconductors, electrodes, interfaces) become electronic ink products, and are printed as such by using inkjet printing techniques.

By 2009, Disa Solar had already placed solar cells on the tops of trains and the results have been excellent.

“We focused on OPV as it can be manufactured with printing technology,” Poughon said. “We are inkjet specialists, and tailor-make products for our customers. We are manufacturing solar panels for trains, electric cars and French Army vehicles. We have a three-year contract with the French Army. ”

R&D is critical to the field of OPV, and DisaSolar is putting great emphasis on research. DisaSolar is working with numerous leading research centers, including CEA, CNRS, Holst Centre, imec and TNO, besides its own research team. All together, DisaSolar manages and coordinates a 25-member R&D team.

“Every time we hear something promising, we work to bring it back to our products,” Poughon said. “We know that efficiency and lifetimes are lower for OPV, but this enables us to focus on specific markets. Actually, 6% efficiency of OPV is more like 9% for other technologies, as increased temperatures improve OPV efficiency but reduce efficiencies for other technologies.”

While OPV has its drawbacks in terms of efficiencies and lifetimes, Poughon noted that OPV is ideal for certain markets. DisaSolar has its eye on key markets, such as power for portable electronic devices like laptops and smartphones; outdoor remote location solutions, including tents, awnings or tarps; transportation, such as trains, buses, airplanes and cars; and automotive charging systems and radios.

DisaSolar customizes its flexible OPV cells by shape, size, color and voltage. One of the keys to DisaSolar’s success is its willingness to produce what their customer needs, rather than insist that one products fits all applications.

“You have to make product special for customers, and you need to pick the right products and sizes,” Poughon concluded. “For example, we can produce different colors for our cells, such as camouflage for the French Army. There is also never the same requirement for space; on a bus, a solar panel can be one meter square or it can be larger. You have to be able to meet your clients’ expectations, not the other way around.”