Nature Energy publishes two‑year field data on perovskite silicon tandem stability
Priya Nair ·
Researchers at Helmholtz‑Zentrum Berlin and Oxford PV report in Nature Energy today that perovskite silicon tandem mini modules maintained output over two years of outdoor operation in Berlin and Oxford, with degradation broadly comparable to conventional silicon. The study links real world performance to established accelerated aging protocols, addressing a central concern for insurers and project finance.
The most consequential result is the reported correlation between International Electrotechnical Commission stress tests and field data once early light induced burn in is accounted for. The team found that after an initial stabilization period, annualized power loss stayed within the range typically underwritten for silicon modules, depending on encapsulation and device stack.
Field data on tandem stability
Led by Steve Albrecht at Helmholtz‑Zentrum Berlin, the group deployed encapsulated tandem mini modules under continuous maximum power point tracking at two instrumented sites. Irradiance, temperature, and spectral content were logged alongside current voltage sweeps to separate thermal and spectral effects from intrinsic device change.
The authors compared monthly yield and temperature coefficients with results from damp heat, thermal cycling, and ultraviolet exposure following IEC 61215 procedures. They report that indoor tests predicted the relative ranking of device stacks seen in the field within stated uncertainties, which supports use of existing qualification workflows rather than bespoke protocols.
Devices under test were small area and used architectures common in current pilot lines, including textured silicon bottom cells and mixed cation perovskite top cells with wide bandgap formulations. The paper notes sensitivity to perovskite composition and interlayer chemistry, and identifies encapsulant selection as a major lever for suppressing moisture ingress and halide migration.
Why it matters for manufacturers
The dataset is limited to temperate European climates and mini modules, and does not include full life cycle analysis or mitigation of lead release in breakage scenarios. The authors call for multi site trials in hotter and more humid locations, and for scaling studies on meter scale modules.
Coauthor Chris Case at Oxford PV positions the work as evidence that tandem stability can be engineered within present materials and process windows. Independent metrology support from European test labs is cited to strengthen claims of reproducibility, although long duration studies beyond two years are still needed.
For the broader technology landscape, field validated stability at the device level reduces nontechnical risk for companies considering tandem upgrades to heterojunction or tunnel oxide passivated contact lines. It gives procurement teams and lenders a basis to evaluate warranty terms, and it puts pressure on materials suppliers to qualify perovskite precursors, barrier films, and interlayers at photovoltaic scale.