In Brief
Thin-film Solar Modules Are Made More Efficient
A team at the Research Centre Jülich have improved the light management in silicium thin-film solar cells and thus have managed to achieve a degree of efficiency of ten percent in a surface area of over one square metre. "Around a third of module performance can be put down to light management, that is, the improved exploitation of captured light", explains Dr Jürgen Hüpkes from the Research Centre Jülich, who coordinated the project LIMA. In addition to the silicium layer in which the captured light is transformed into electric energy, the electric contact layers or electrodes are of particular importance for the functioning of a solar cell. On the one hand they dissipate the electricity and on the other they influence the path the light takes within the silicium. The longer the path, the more energy is transformed within the solar cell.
The procedures for producing the electrodes as well as their surface wrinkling were decisively optimised in the course of the project LIMA. It now is possible to cost-efficiently produce the less than a thousandth millimetre thin layers with the required characteristics on a surface of more than five square metres. The first industrially solar modules produced using this newly developed process have an efficiency of 10.6 percent, which is a record high for solar cells based on this thin-layer technology.
In addition to the Research Centre Jülich heading this project, participation included the companies Applied Materials, Sentech Instruments, Sunfilm, Schott Solar Thin Film, Saint-Gobain Sekurit, Malibu Solar, the Helmholtz Centre Berlin, the Fraunhofer Institute for Surface Engineering and Thin Films and the RWTH Aachen. The three and a half-year project was funded by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety with 4.4 million Euro.
