With its newest solar cell, German research organization Fraunhofer has managed to exceed the world record for multicrystalline silicon cells. The new cells convert an impressive 22.3% of incident solar energy into electricity, and the researchers think that the limits have not yet been reached. Given that the previous world record was also set by Fraunhofer just a few months, we wouldn’t bet against it being able to raise the bar even higher.
Monocrystalline solar cells are the most efficient cells that are used today, but the large amount of energy needed to manufacture them makes them expensive to produce. Multicrystalline cells are produced by melting silicon and then cooling it, which uses less energy and makes the cells cheaper as a result. The downside is that multicrystalline cells are less efficient. You can find a detailed account of the different types of solar PV in our recent article outlining predictions for the industry.
Narrowing the efficiency gap
Holding a market share of 57%, multicrystalline cells are the most commonly used cell in the photovoltaic industry. Narrowing the gap in efficiency between monocrystalline cells and multicrystalline cells therefore has huge benefits. This work by Fraunhofer has the potential to further reduce the cost of solar electricity and would have a wide-reaching impact
Fraunhof achieved the record by making adjustments that focused on the needs of the multicrystalline material in the cell processing steps and in crystallization, and by using a highly pure silicon. The team also used a “Tunnel Oxide Passivated Contact Technology (TOPcon)” which had been developed by Fraunhofer. This technology leads to higher electrical efficiencies by reducing carrier-loss, a result of of applying the electrical contacts to the rear surface of the cell without patterning.
In a statement, Division Director Prof. Stefan Glunz said: “These successful results achieved in solar cell efficiency are based on steady, continuous development and demonstrate the strength of European research and innovation in this field. At the same time these advances lead the way for Europe’s entry into market production of the next generation technology on the global scale.”
More than a decade of pioneering research
In 2016, Fraunhofer celebrated the 10th anniversary of its research factory, marking a decade of service to the German PV industry, and opened a new “PV-TEC Select” laboratory. At that time Dr. Jochen Rentsch, Laboratory Head of PV-TEC Select, revealed its big goal: “In our new laboratory addition, our aim is to produce solar cells with efficiencies up to 25% as well as offer industry a unique chance to evaluate equipment technology on pilot scale in a clean room environment.” These great results are the clear fruits of that labor. With the new world record being set, Fraunhofer is on course to hit this ambitious target, and continue to be a world leader in the photovoltaic industry.