Fraunhofer ISE and University of Freiburg develop transparent solar modules

Researchers from the Fraunhofer Institute for Solar Energy Systems (ISE) and the University of Freiburg have achieved a breakthrough in developing semitransparent organic photovoltaic (OPV) modules that can be produced using industrial processes.

These modules, measuring 14.5 by 14.5 centimeters, feature an average light transparency of 43.2 percent and an efficiency of up to 9.26 percent. The technology utilizes carbon-based semiconductors to convert light into electricity, offering the potential to turn windows, glass facades, and car roofs into power generators. This could significantly expand solar energy capacity without requiring additional land area, a critical factor as Germany faces land constraints for renewable energy expansion.

The production process utilizes established industrial methods: sputtering is used to apply back electrodes to glass, while slot-die coating is employed for subsequent layers. The research team also successfully produced flexible organic PV modules on foil. This scalability addresses a major challenge in organic photovoltaics, where laboratory-scale results often fail to translate directly to large-scale industrial formats.