HZB Reports 32.5% Efficiency For Tandem Solar Cells

• HZB has reported achieving 32.5% efficiency for perovskite-silicon tandem solar cell
• It was able to achieve the level with 'advanced' perovskite configuration uses a 'very smart interface modification'
• The institute's claim has been officially confirmed by the ESTI and has also found its way on the NREL chart

German research center Helmholtz Zentrum Berlin (HZB) has announced a new world record power conversion efficiency of 32.5% for perovskite-silicon tandem solar cell, officially confirmed by the European Solar Test Installation (ESTI) and on the charts of the National Renewable Energy Laboratory (NREL).

"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," said HZB Scientific Director Prof. Bernd Rech.

The winning configuration had perovskite as the top cell and silicon as the bottom cell. The 'advanced' perovskite configuration uses a 'very smart interface modification' that helped reduce charge carrier recombination losses.

Without sharing too many details, the HZB team claims the interface and optical modifications enabled highest photovoltages (open-circuit voltage) leading to the new record efficiency.

This efficiency is an improvement over 29.8% it reported in late-2021, which was dethroned by Switzerland's Ecole Polytechnique Fédérale de Lausanne when it announced 31.3% efficiency (see Record Tandem Cell Efficiency Made In Switzerland).

Now, EPFL is back on the top with 32.5% efficiency. "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," shared HZB Professor Steve Albrecht.

At the recent TaiyangNews' High Efficiency Solar Conference 2022, Prof. Gianluca Coletti from Dutch research organization TNO presented an Outlook on Next Generation Solar Cell Technologies, with emphasis on silicon-perovskite tandem cells, which can be viewed here.