New record for perovskite-silicon tandem solar cells: 32.5% efficiency achieved

A few days ago the news of a new record in the field of pervoskite-silicon tandem solar cells was released, arrive at 32.5% efficiency.

The module has also been certified by third parties, such as L’European Solar Test Installation (ESTI)a European reference laboratory for calibration of photovoltaic devices and verification of their energy generation.

Founded in the late 70’s, it was also at the forefront of developing international standards for the evaluation of the electrical performance of photovoltaic products and for their reliability.

The solar cell has also been included in the Best Research-Cell Efficiency Chart of the U.S. National Renewable Energy Lab.

Of this particular type of photovoltaic cells, which they exploit the properties of silicon and pervoskite, uniting them in a “tandem”we spoke several times, citing various studies that led the search to surpass, on every occasion, the previous record.

You can find the articles here: link, link, link.

The last, in chronological order, had been reached by the photovoltaic laboratory of theEPF (Ecole Polytechnique Fédérale de Lausanne, Switzerland)in collaboration with the innovation center CSEMwhich had achieved an efficiency of 31.25% with a 2 terminal architecture.

German researchers have fielded another strategy, using “an advanced composition of perovskite with a very clever interface modification”.

The lead authors of the research, Dr. Silvia Mariotti and Dr. Eike Köhnen from the Albrecht teamhave developed an interface modification to reduce the losses of recombination of charge carriers applying detailed analysis to understand the specific properties of the interface change.

These developments were then successfully implemented in tandem solar cells and, with the help of the Master’s student Leah Zimmermanncombined with further optical improvements.

The interface and optical changes have allowed higher photovoltages (i.e. open circuit voltage), leading to the achievement of the new efficiency record.

“We are very excited about the new value as it demonstrates that perovskite/silicon tandem technology holds great promise for contributing to sustainable energy supply” said Albrecht’s team.

The scientific director of HZB, Prof. Bernd Rech, then underlined: “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 chart clearly shows how spectacular the last two increases from EPFL and HZB really are.”.