30 Sept 2025

Perovskite-silicon tandem cell reaches certified 28.9% efficiency at 60 cm²

Energy and storage
AI illustration · Illustrative scene, not a photograph of the specific device or experiment.

What was demonstrated

A perovskite-silicon tandem solar cell with a 60 cm² active area reached a certified steady-state efficiency of 28.9%, certified by Fraunhofer ISE CalLab. The reverse-scan efficiency was 29.0%, with an open-circuit voltage of 1.965 V, a short-circuit current density of 18.87 mA/cm² and a fill factor of 77.94%. Two batches of eight large-area devices averaged 29.5% efficiency. The authors used phosphonic-acid and piperazinium chloride treatments to passivate the perovskite layer, which is the same passivation approach as their 1 cm² cells that reached a certified 31.6% steady-state efficiency.

Why it matters

The authors report that the passivation approach, which increased the perovskite quasi-Fermi level splitting by about 100 mV, carried over from a 1 cm² research cell to a 60 cm² device. This suggests that uniform surface treatments may help tandem cells keep their efficiency as area increases. The paper does not report stability for the 60 cm² device, so whether the effect lasts is not yet established.

Caveats

  • This is a laboratory device. The 60 cm² bottom cell omitted some 1 cm² features, and shadowing losses from the metal fingers were estimated at about 2.85%, compared with about 1.5% for 1 cm² devices.
  • The paper's maximum power point tracking test was run on separate single-junction devices, not on the 60 cm² tandem. Under nitrogen at about 35 °C, without encapsulation, efficiency fell from 21% to 16% after 115 hours. The authors attribute this to ionic losses and a weakened perovskite/C60 interface.
  • The result is not a full-size commercial module. Long-term outdoor stability and manufacturing yield were not established in the paper.

Technology profiles

Sources

  1. peer reviewed paper
    60 cm² perovskite-silicon tandem solar cells with an efficiency of 28.9% by homogeneous passivation
    Kerem Artuk, Aleksandra Oranskaia, Deniz Turkay et al.. Nature Communications, 30 Sept 2025. DOI: 10.1038/s41467-025-63673-y.

Last reviewed 21 Oct 2026.