A new collaborative research on perovskite–silicon tandems came out in Science! Record 33.1% efficiency with an open-circuit voltage of 2.01 V

September 5, 2025

PDAI₂ surface treatment enables electron accumulation across the perovskite layer and results in highly efficient tandems with conformal coated perovskites on textured interfaces

Reducing charge carrier transport losses, improving selectivity, and minimizing non-radiative recombination are key challenges in advancing perovskite/silicon tandem solar cells. In a new study published in Science, our collaborative team lead by Fraunhofer ISE and KAUST (a work initiated during the period of Dr. Aydin at KAUST) reports a major breakthrough: a fully-textured tandem device reaching 33.1% efficiency and 2.01 V open-circuit voltage, setting a new benchmark for this technology.

The team developed a hybrid two-step perovskite deposition method compatible with industry-standard textured silicon and introduced a surface treatment with 1,3-diaminopropane dihydroiodide (PDAI₂). This treatment induced electron accumulation across the entire perovskite absorber, reducing transport losses and interfacial recombination simultaneously. As a result, the devices achieved both higher conductivity and improved fill factor—an effect often overlooked compared to interfacial passivation.

Advanced characterizations, including opto-electrical simulations, sub-cell-selective imaging, and suns-V_OC analysis, confirmed that the PDAI₂-induced field-effect passivation enhances electron transport throughout the bulk absorber. Interestingly, while PDAI₂ also modified the surface dipole, the crucial benefit came from minimizing the conduction band offset at the electron contact. This finding highlights a new design principle: increasing ionization potential is more critical than dipole direction for effective passivation.

The optimized architecture not only delivers record performance but also shows extended operational stability under outdoor conditions, including suppression of ion migration across the perovskite/C₆₀ interface. Together, these results demonstrate the true potential of industry-compatible textured perovskite/silicon tandems for future large-scale commercialization.

You can reach the full text of teh article via the link.