Semi-transparent photovoltaics could significantly increase the surface area that can be used for a climate-friendly energy supply. In the SEMTRASOL research project, researchers at the Karlsruhe Institute of Technology (KIT) are developing solar cells with precisely adjustable absorption properties and high efficiency.
"While silicon photovoltaics are used ubiquitously today to generate energy, the benefits of organic solar cells have so far been vastly underestimated. As a result, there has been no major breakthrough on the market so far," says Dr. Christian Sprau from the Institute of Light Technology at KIT. With his recently launched research group and the SEMTRASOL research project, he wants to change this: "With new material concepts and the latest organic semiconductors, it is becoming increasingly possible to precisely control the absorption properties of organic solar cells and achieve a high application-specific efficiency." This makes highly efficient photovoltaics on glass fronts conceivable, for example, which are no longer noticeable.
Organic solar cells use carbon-based semiconductors, which are typically characterized by narrow-band absorption ranges. Thanks to the development of new types of acceptors, i.e. the electron-accepting molecules in the light-absorbing layer in a solar cell, they can now achieve efficiencies of up to 20 % in the laboratory. According to the KIT research team, double land use by photovoltaics will play an important role in enabling Germany and Europe to achieve climate neutrality in time. The technological prerequisites have been met, and SEMTRASOL now aims to combine them. "It's not trivial, but I'm convinced that semi-transparent solar cells will be part of our everyday lives in the not too distant future," says Sprau.
