PARIS – Researchers from the Karlsruhe Institute of Technology (KIT) have launched a four-year research program that aims to improve the efficiency of organic solar cells to more than 10 percent.
Organic solar cells are cheaper to produce, lighter and more flexible than traditional silicon-based solar cells, opening new perspectives in particular for the architectural design of buildings. Solar modules can be integrated in facades and even windows. The downside is that the efficiency rate of OPV cells remains much lower than inorganic solar cells, demonstrating 15-20 percent efficient.
Led by Dr. Alexander Colsmann, at KIT's Light Technology Institute, the newly-launched project uses tandem architectures. Two solar cells with complementary absorption characteristics are stacked directly on top of each other to achieve better sunlight harvesting and more efficient energy conversion.
The KIT scientists said they use novel materials, develop innovative device architectures, optimize their stability, and test the solar cells in a real-life environment. They also intend to transfer manufacturing processes from the laboratory to an industry-compatible production environment so as to promote future commercial use of their results.
Source KIT
The project received a 4.25 million euro ($5.35 million) funding from the Federal Ministry of Education and Research.
It has also received the support of the Fraunhofer Institute for Applied Polymer Research (IAP), Potsdam, and the University of Queensland/Australia, which supplies new materials for organic solar cells. Merck KGaA is the industry advisor of the project.
Recently, Heliatek GmbH (Dresden, Germany) claimed it had pushed the record efficiency for organic solar cells higher, achieving an efficiency of 10.7 percent in a 1.1 square centimeter tandem cell. Measurements, led by independent test house SGS SA (Geneva Switzerland), showed that the cell improved efficiency under low light conditions and that the efficiency remains constant with temperature.
