A group of German scientists achieved two new world efficiency records for OPV modules: 12.6% in an area of 26 cm2 and 11.7% in an area of 204 cm2.
The distance between organic photovoltaic modules and traditional silicon panels is shortened.
Around the world, solar research continues to bet on photoactive polymers, molecules and dyes as substitutes for the more expensive inorganic semiconductors.
However, the practical result, in terms of performance and stability, still represents a significant marketing disadvantage.
For its part, the promise of profitability, together with the flexibility and lightness of the final products, synonymous with excellent integrability, keep scientific interest alive.
Organic solar cells are, in fact, normally composed of two different components that possess the necessary semiconductor properties.
The latest advances in this field have been achieved by a German research group that has managed to set two world records for organic photovoltaic modules in the last year.
The credit goes to scientists from the Friedrich-Alexander University, the Bavarian Center for Applied Energy Research and the Helmholtz Institute for Renewable Energy. The team, led by Andreas Distler, published the results of the work in the scientific journal Progress in Photovoltaics.
In recent years, the development of new active materials has led to a constant improvement in the energy conversion efficiency of organic photovoltaic energy processed in solution, to record values of more than 17% in small laboratory cells.
But it is one thing to obtain a certain performance on surfaces in the order of millimeters, it is another to be able to replicate the success on a useful scale for the market.
Due to the design, the efficiency of the complete panels is always slightly lower than that of the individual cell. For example, part of the module area is idle because it is used to interconnect individual cells. As the surface area increases, the losses due to the electrical resistance of the electrodes also increase.
To minimize these problems, scientists have turned to layout optimization and a short pulse (nanosecond) laser structuring process. In this way they were able to almost completely eliminate losses due to imperfections during production, minimizing idle areas.
The result? The new organic photovoltaic modules show an efficiency of conversion of light into electricity of 12.6% in an area of 26 square centimeters and 11.7% in an area of 204 square centimeters. Both values have been independently certified by the Fraunhofer ISE.
The news was particularly well received by the Bavarian Ministry of Economic Affairs, Hubert Aiwanger: “ This development shows that Bavaria is not only a leader in the expansion of photovoltaic energy, but also occupies a leading position in the development of future technologies . “