Scientists from Helmholtz-Zentrum Berlin achieved the world record for highest efficient tandem solar cell with silicon bottom and perovskite top cells. European Solar Test Installation, the certifying institute officially confirmed the 32.5% efficiency of these solar cells. With this a new world record with the highest efficiency tandem solar cells by HZB is created.
Various research institutes and companies are working on an ongoing efficiency development study. But teams from HZB had achieved a new certified record value of 32.5% efficiency of solar cell. This is not the first time they achieved the highest efficiency because in 2021 HZB achieved the record value of 29.8% that was realized by periodic nanotextures. Then in summer 2022, the highest recorded efficiency value reported by Ecole Polytechnique Fédérale de Lausanne, Switzerland was 31.3%, finally beyond the 30% barrier. But with 32.5% HZB nailed it once again.
Professor Steve Albrecht from HZB says, “We are very excited about the new value as it shows that the perovskite/silicon tandem technology is highly promising for contributing to a sustainable energy supply.” Scientific director at Helmholtz-Zentrum Berlin, Professor Bernd Rech further emphasizes, “At 32.5%, the solar cell efficiency of the HZB tandems is now in ranges previously only achieved by expensive III/V semiconductors. NREL graph clearly shows how spectacular the last two increases from EPFL and HZB really are.”
Scientists from HZB could significantly improve the efficiency of silicon or perovskite tandem solar cells. Professor Steve Albrecht says, “This is a huge leap forward that we didn’t foresee a few months ago. All the teams involved at HZB, especially the PV Competence Center (PVComB) and the HySPRINT Innovation lab teams have worked together successfully and with passion.” An advanced perovskite composition with a very smart interface modification was used by the team.
Lead authors, in Professor Albrecht’s team, Dr. Eike Köhnen and Dr. Silvia Mariotti developed an interface modification to reduce charge carrier recombination losses. Further to understand the specific properties of this interface modification, detailed analysis was applied. Then these developments were successfully implemented in tandem solar cells.
Lea Zimmerman, a Master’s student, helped in further combining it with optical improvements. Highest photovoltages (open circuit voltage) was achieved with the combination of interface and optical modifications that further resulted in new record-breaking efficiency for tandem technology.
Also Read: What is the Solar Angle of Incidence?
Many more technicians and scientists helped in development and fabrication of tandem solar cells to make this project a success. And towards the end of 2022, Meyer Burger Technology signed a multi-year cooperation agreement with various research institutes in Switzerland and Germany, including Helmholtz-Zentrum Berlin, to industrialize perovskite tandem solar cells and modules.
A new world record with the highest efficiency tandem solar cells by HZB along with the industrialization agreement is expected to produce 321.1-megawatt energy.