At the beginning of the year, PEPPERONI published two scientific articles about the latest stability test results of perovskite/silicon tandem solar cells, aimed at achieving the full performance potential of perovskite photovoltaic (PV) modules. One of the publications from project partners at Helmholtz Zentrum Berlin (HZB), titled “Mimicking Outdoor Ion Migration in Perovskite Solar Cells: A Forward Bias, No-Light Accelerated Aging Approach” and published in ACS Energy Letters, has been spotlighted in the Scientific Highlights section of nature energy in April, and now again within the global news section of PV magazine.
The article highlights HZB’s novel accelerated ageing protocol for perovskite solar cells, during which devices are cycled between prolonged forward electrical biasing and dark rest periods, both conducted in the absence of light. Under forward bias, accelerated ion migration raises recombination, impedes charge transport, and generates defect growth. A subsequent dark rest leads to partial recovery in performance but leaves the device in a more degradation-prone, high-recombination state. These ageing dynamics strongly mirror observations from a 20‑month outdoor field test in Berlin, Germany, where warmer, brighter seasons align with forward bias stress and cooler periods with rest, demonstrating that this simplified, single‑stress method effectively replicates real-world outdoor degradation.
This method offers a low-cost, scalable alternative to expensive illumination-based ageing tests, especially beneficial for full‑size PV modules that are challenging to stress under continuous light. The electric bias routine could become a practical quality assurance tool, capturing important ion‑migration degradation modes using straightforward electrical setups. HZB’s team plans to extend this work by testing the protocol across different module designs and exploring whether additional degradation processes can be accelerated through this method.