Perovskite/Silicon Tandem Solar Cells Reaches 30% Efficiency

Solar cells, which consist of two semiconductors with different bandgap, can achieve significantly higher efficiency when used in tandem than when used alone. This is because tandem cells use the solar spectrum more efficiently. In particular, traditional silicon solar cells primarily efficiently convert the infrared component of light into electrical energy, but this is a powerful combination because certain perovskite compounds can effectively utilize the visible component of sunlight.

In early 2020, a team led by Professor Steve Albrecht of Helmutholtz Zentrum Berlin (HZB) in Germany broke the previous world record (28.0%, Oxford PV) for tandem solar cells made of perovskite and silicon, setting a new world record of 29.15%. did. This is a huge step forward when compared to the highest certified and scientifically announced efficiency (DOI 26.2%: 10,1126 / science.aba3433). The new values ​​have been certified by Fraunhofer ISE and are listed on the NREL chart.Results are currently published in the journal Science With a detailed description of the manufacturing process and the underlying physics.

29.15% efficiency is not only a record for this technology, but also at the top of the overall Emerging PV category on the NREL chart,” said Eike Köhnen, PhD student and lead author of the study on the Albrecht team. .. In addition, the new perovskite / silicon tandem cell features consistent performance for over 300 hours under continuous exposure to air and simulated sunlight, unprotected by encapsulation. .. The team took advantage of a complex perovskite composition with a bandgap of 1.68 eV and focused on optimizing the substrate interface. The researchers analyzed the two cells individually and calculated the maximum efficiency of 32.4% possible with this design. “You can certainly achieve more than 30%,” says Albrecht.