Tandem solar cell achieves 32.5% effectivity

The present world document of tandem solar cells consisting of a silicon backside cell and a perovskite high cell has as soon as once more been damaged at HZB. The new tandem solar cell converts 32.5% of the incident solar radiation into electrical power. The certifying institute European Solar Test Installation (ESTI) in Italy measured the tandem cell and formally confirmed this worth which can be included within the NREL chart of solar cell applied sciences, maintained by the National Renewable Energy Lab, U.S..

Scientists from HZB might considerably enhance on the effectivity of perovskite/silicon tandem solar cells. “This is a really big 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,” says Prof. Steve Albrecht.

Interface modifications

Albrecht’s staff used a complicated perovskite composition with a really good interface modification. The lead authors, postdocs Dr. Silvia Mariotti, and Dr. Eike Köhnen in Albrecht’s staff, developed an interface modification to scale back cost service recombination losses and utilized detailed evaluation to grasp the precise properties of the interface modification. These developments have been then efficiently applied in tandem solar cells, and with assist of Master’s scholar Lea Zimmermann, mixed with additional optical enhancements.

In addition, many extra scientists and technicians helped to develop and fabricate the tandem cells to attain this success. Altogether, the interface and optical modifications enabled highest photovoltages (open-circuit voltage) and resulted within the new document effectivity for this fascinating tandem expertise.

Fast progress

Ongoing effectivity growth by varied analysis institutes and corporations during the last years and particularly the final month have been fairly thrilling for the sector: Various groups from HZB achieved a document worth in late 2021 with an effectivity of 29.8% that was realized by periodic nanotextures. More lately, in summer season 2022, the Ecole Polytechnique Fédérale de Lausanne, Switzerland, first reported an authorized tandem cell above the 30% barrier at 31.3%, which is a exceptional effectivity bounce over the 2021 worth.

With the brand new licensed worth of 32.5%, the document is once more again at HZB. “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,” says Albrecht.

HZB’s scientific director, Prof. Bernd Rech, says, “At 32.5%, the solar cell efficiency of the HZB tandems is now in ranges previously only achieved by expensive III/V semiconductors. The NREL graph clearly shows how spectacular the last two increases from EPFL and HZB really are.”