At present growth in the solar industry is held back by the fact that the production of silicon-based solar modules is rather expensive and consumes a lot of energy. One alternative could be cheaper solar and photovoltaic cells made from organic materials that would enable the construction of innovative displays, solar tarpaulins and solar windows. Currently, several projects are being carried out which are aimed at researching new materials, production processes and installation technologies in this area. The Helmholtz Centre in Berlin, formerly the Hahn-Meitner Institute, has been working on this topic since 2001.

Organic solar cells are regarded as good light absorbers, but they do have the disadvantage of being bad conductors. They are not made from traditional semiconductor material but from pigments and other hydrocarbon compounds – applied to a carrier material such as glass or film. These materials can be mass produced and only a few grams are needed to coat several square meters of film. Accordingly, material costs are irrelevant. The deposited layers are only a few nanometers thick and thus a lot thinner than previous thin-layer films based on inorganic materials (CIS cells).

The Helmholtz Centre in Berlin, formerly the Hahn-Meitner Institute recognized this potential at a relatively early stage. The first functioning cells were already produced in 2001 within the scope of the "Organic Solar Cells" project funded by the German Federal Ministry of Education and Research (BMBF). On the basis of this feasibility study, in which both the Helmholtz Centre and the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg are participating, scientists plan to find out if it would be worthwhile increasing activities in this area. Between 2003 and 2007, within the scope of the Organic Vapor Phase Deposition project, the Berlin team developed a new coating process that enables higher throughput in the production of organic solar cells. While in organic photovoltaics the light-absorbing layers are usually applied from a solution by dipping, spraying or rotation coating, scientists at the Helmholtz Centre were able to transport the materials to the substrate surface, with the help of a carrier gas, where they are quickly deposited. The scientists were also able to integrate the relays into the production process and thus ensure that the complicated contacting process is superfluous. This considerably reduces manufacturing costs. In this way the researchers produced a functioning mini-module with an area of around 25 cm². The underlying solar cell concept, a mixture of fullerene and phthalocyanine, currently has an efficiency level of 3 percent.

At present, research into "organic solar cells" is still facing two serious problems. On the one hand, the aim is to increase the life of the cells from around a few months to three years. Another challenge is to increase the efficiency to at least 8 percent. Scientists at the Helmholtz Centre are pursuing the goal of increasing the efficiency in a project called "self organization in organic hybrid solar cells", which is to start this year and run for three and a half years. It is just one of 15 projects in the "organic photovoltaics" initiative, which was launched last year by the German Federal Ministry for Education and Research (BMBF) in cooperation with the industry, and is sponsored to the tune of 360 million euros. Scientists at the Berlin-based centre aim to increase the efficiency of the cells with the help of nanotechnological methods.
Potential areas of application for organic solar cells are cell phone displays, glass facades, tent roofs and solar windows.