De Bastiani, MicheleVan Kerschaver, EmmanuelJeangros, QuentinRehman, Atteq UrAydin, ErkanIsikgor, Furkan H.Mirabelli, Alessandro J.Babics, MaximeLiu, JiangZhumagali, ShynggysUgur, EsmaHarrison, George T.Allen, Thomas G.Chen, BinHou, YiShikin, SemenSargent, Edward H.Ballif, ChristopheSalvador, MichaelDe Wolf, Stefaan2021-09-112021-09-112021-09-112021-08-1310.1021/acsenergylett.1c01018https://infoscience.epfl.ch/handle/20.500.14299/181334WOS:000686077800033Perovskite/silicon tandem solar cells are emerging as a high-efficiency and prospectively cost-effective solar technology with great promise for deployment at the utility scale. However, despite the remarkable performance progress reported lately, assuring sufficient device stability-particularly of the perovskite top cell-remains a challenge on the path to practical impact. In this work, we analyze the outdoor performance of encapsulated bifacial perovskite/silicon tandems, by carrying out field-testing in Saudi Arabia. Over a six month experiment, we find that the open circuit voltage retains its initial value, whereas the fill factor degrades, which is found to have two causes. A first degradation mechanism is linked with ion migration in the perovskite and is largely reversible overnight, though it does induce hysteretic behavior over time. A second, irreversible, mechanism is caused by corrosion of the silver metal top contact with the formation of silver iodide. These findings provide directions for the design of new and more stable perovskite/silicon tandemsChemistry, PhysicalElectrochemistryEnergy & FuelsNanoscience & NanotechnologyMaterials Science, MultidisciplinaryChemistryScience & Technology - Other TopicsMaterials Sciencesolar-cellsinduced degradationstabilitylightmigrationdesignheattext::journal::journal article::research article