New efficiency record for solar cell technology

A new world record solar cell efficiency for silicon perovskite tandem solar cells has been achieved, with German scientists converting 32.5% of sunlight into electrical energy.

The Helmholtz Centre Berlin Materials and Energy (HZB) in Germany has once again broken the current world record for a tandem solar cell consisting of a silicon bottom cell and a perovskite top cell.

The team has developed a new tandem solar cell that converts his 32.5% of incident solar radiation into electrical energy. The Italian certification body European Solar Test Installation measured the tandem cell and officially confirmed this value.

It is also included in his NREL chart (see chart below) for solar cell technology maintained by the US National Renewable Energy Laboratory. This breakthrough could significantly improve the efficiency of commercial perovskite/silicon tandem solar cells.

New efficiency record for solar cell technology

This is a really big leap forward that we didn’t foresee a few months ago,” says Prof. Steve Albrecht. “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.”

His team used advanced perovskite compositions to modify very smart interfaces. Principal author, postdoctoral fellow Dr. Silvia Mariotti and her Eike Koehnen of Dr. Albrecht’s team, developed a method to reduce charge carrier recombination losses and applied detailed analysis to characterize the specific properties of the interface modification. understood. These developments were then successfully implemented in a tandem solar cell and combined with further optical refinements with the help of master’s student Lea Zimmermann.

Moreover, many other scientists and engineers assisted in the design and fabrication of tandem cells to achieve this achievement. Overall, the interface and optical changes allow the highest optical voltage (open circuit voltage) and new record efficiency.

Credit: Eike Köhnen/HZB

There is an ongoing efficiency drive by various research institutes and companies, which over the last few years and especially the last month has been quite exciting for the field: teams from HZB had achieved a record value in late 2021 with an efficiency of 29.8% that was realised by periodic nanotextures. More recently, in summer 2022, the Ecole Polytechnique Fédérale de Lausanne, Switzerland, first reported a certified tandem cell above the 30% barrier at 31.3%, which is a remarkable efficiency jump over the 2021 value.

With the new certified value of 32.5%, the record is again back 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, emphasises: “At 32.5 percent, 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.”

Recent advancements in solar cell technology have set new records for efficiency and cost-effectiveness, making it a viable alternative to traditional forms of energy generation. The potential for solar energy to meet the increasing energy demands of the world is significant. For more information about the future state of solar cell technology and its role in the transition to renewable energy sources, check out our article From Research To Reality: The Current And Future State Of Solar Cell Technology.