A tandem solar cell, made up of a silicon bottom cell and a perovskite top cell, has set a new world record for converting solar radiation into electricity at HZB. The cell achieved a conversion rate of 32.5%, which has been verified by the European Solar Test Installation (ESTI) in Italy and included in the National Renewable Energy Lab’s (NREL) chart of solar cell technologies in the United States.
A team of scientists at HZB have made a significant advancement in the efficiency of perovskite/silicon tandem solar cells. “We didn’t expect this level of progress a few months ago, so it’s a really big leap forward,” said Prof. Steve Albrecht. He went on to praise the efforts of the PV Competence Center (PVComB) and the HySPRINT Innovation lab teams at HZB, stating that they “worked together successfully and with passion.”
The team at HZB, led by Prof. Steve Albrecht, used an advanced perovskite composition and an interface modification to improve the efficiency of tandem solar cells. Dr. Silvia Mariotti and Dr. Eike Köhnen, postdocs in Albrecht’s team, developed the interface modification to reduce charge carrier recombination losses and conducted detailed analysis to understand its specific properties. These modifications, along with further optical improvements and the efforts of many other scientists and technicians, enabled the tandem cells to achieve their highest photovoltages (open-circuit voltage) and set a new record efficiency for this technology.
Efficiency development in the field of tandem solar cells has been a focus of various research institutes and companies in recent years, and especially in the past month. In late 2021, teams from HZB achieved a record efficiency of 29.8% using periodic nanotextures. More recently, in summer 2022, the Ecole Polytechnique Fédérale de Lausanne in Switzerland reported a certified tandem cell with an efficiency of 31.3%, a significant increase over the previous record set in 2021. These achievements are exciting for the field and demonstrate the potential for further progress in tandem solar cell efficiency.
HZB’s tandem solar cell, which consists of a silicon bottom cell and a perovskite top cell, has set a new world record with an efficiency of 32.5%, confirmed by the European Solar Test Installation (ESTI) in Italy. “We are very excited about the new value as it shows that the perovskite/silicon tandem technology has great potential for contributing to a sustainable energy supply,” said Prof. Steve Albrecht. Prof. Bernd Rech, the scientific director at HZB, added that the efficiency of the HZB tandems is now in the range previously only achieved by expensive III/V semiconductors, and that the recent increases in efficiency from HZB and the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland are “spectacular,” as shown on the NREL graph.
SOURCE: Tech Explore