The Karlsruhe Institute of Technology, through its Light Technology Institute, this month will initiate new research on printable organic solar cells. The four-year project aims at increasing the efficiency of such cells to more than 10 percent. These promising, cheaper solar cells can be manufactured using existing techniques such as screen printing and continuous roll-to-roll processes. So far, however, low efficiency rates have stood between these cells and the market.

The methodology the KIT researchers are going to use is based on a tandem architecture, which involves combining multiple solar cells that offer complementary levels of light absorption. They stack two solar cells directly on top of each other and together they can harvest more sunlight and, consequently, achieve better efficiency rates.

Organic solar cells are also known as plastic solar cells. They are light, flexible, semi-transparent, more environmentally-friendly than other types of cells, and offer a quicker return on investment. Such characteristics open up possibilities for exciting new applications, especially in architecture, where the cells could be integrated into the design of buildings. Other areas offering potential for the technology include the manufacturing of automotive parts and consumer goods.

The research will also look into new materials, as well as ways to improve the cells’ stability. All testing will be done in real-life contexts, including manufacturing processes, which will be done in an industry-compatible production environment in order to improve chances of commercially-applicable results.

KIT researchers are not the only ones working to improve organic solar cell efficiency, but if they achieve their desired goal, this type of solar cell could get closer to becoming competitive with standard, non-organic silicon models.

The research has been made possible with €4.25 million (US$5.32 million) in funding from the German Federal Ministry of Education and Research.