Electricity from a thin film

Researchers at The Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany are working towards the industrial mass production of organic solar cells.

These cells can be laid onto thin films, which make them cheap to produce and established printing technologies could be used for future production.

However, to achieve suitable solar cell architecture, coating materials and substrates have to be developed.

”This method permits a high throughput, so the greatest cost is that of materials,” said Michael Niggemann, a researcher at ISE.

Organic solar cells are not efficient enough to compete with classic silicon cells yet but because they are flexible they can open up new fields of application, for example, plastic solar cells could supply the power for small mobile devices such as MP3 players or electronic passes.

Another possibility would be to combine solar cells, sensors and electronic circuits on a small strip of plastic to form a self-sufficient power microsystem.

Until now, the front electrode has usually been made of expensive indium tin oxide because this material is transparent. But the Fraunhofer team has found an alternative by interconnecting a poorly conductive transparent polymer electrode with a highly conductive metal layer on the rear side of the solar cell.

This connection is through numerous tiny holes in the solar cell .This has the advantage that a low-priced material can be used.