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Perovskite-Silicon Tandem
Published In

Science

Authors

Jiang Liu,* Michele De Bastiani, Erkan Aydin, George T. Harrison, Yajun Gao, Rakesh R. Pradhan, Mathan K. Eswaran, Mukunda Mandal, Wenbo Yan, Akmaral Seitkhan, Maxime Babics, Anand S. Subbiah, Esma Ugur, Fuzong Xu, Lujia Xu, Mingcong Wang, Atteq ur Rehman, Arsalan Razzaq, Jingxuan Kang, Randi Azmi, Ahmed Ali Said, Furkan H. Isikgor, Thomas G. Allen, Denis Andrienko, Udo Schwingenschlögl, Frédéric Laquai, and Stefaan De Wolf*

Citation

Liu, J.; De Bastiani, M.; Aydin, E.; Harrison, G. T.; Gao, Y.; Pradhan, R. R.; Eswaran, M. K.; Mandal, M.; Yan, W.; Seitkhan, A.; Babics, M.; Subbiah, A. S.; Ugur, E.; Xu, F.; Xu, L.; Wang, M.; Rehman, A. U.; Razzaq, A.; Kang, J.; Azmi, R.; Said, A. A.; Isikgor, F. H.; Allen, T. G.; Andrienko, D.; Schwingenschlögl, U.; Laquai, F.; De Wolf, S. Efficient and Stable Perovskite-Silicon Tandem Solar Cells through Contact Displacement by MgFx. Science 2022, 377, 302–306.

Express Summary
  • In perovskite-silicon tandem solar cells, the presence of C60 molecules at the interface with the perovskite layer can create shallow trap states and lead to high levels of interface recombination, reducing the power conversion efficiency (PCE) of the cells.
  • Addition of an ultrathin metal-fluoride interlayer at the perovskite/C60 interface can reduce nonradiative recombination and improve electron extraction, resulting in a higher PCE of 29.3%.
  • Insertion of an interlayer can also address the issue of a surface dipole at the pristine perovskite/C60 interface, which can hinder electron extraction.
  • (MgF2)n layers serve as a better “electron sink” than (LiF)n layers, enabling more efficient charge extraction.
Abstract

The performance of perovskite solar cells with inverted polarity (p-i-n) is still limited by recombination at their electron extraction interface, which also lowers the power conversion efficiency (PCE) of p-i-n perovskite-silicon tandem solar cells. A MgFx interlayer with thickness of ~1 nanometer at the perovskite/C60 interface favorably adjusts the surface energy of the perovskite layer through thermal evaporation, which facilitates efficient electron extraction and displaces C60 from the perovskite surface to mitigate nonradiative recombination. These effects enable a champion open-circuit voltage of 1.92 volts, an improved fill factor of 80.7%, and an independently certified stabilized PCE of 29.3% for a monolithic perovskite-silicon tandem solar cell ~1 square centimeter in area. The tandem retained ~95% of its initial performance after damp-heat testing (85°C at 85% relative humidity) for >1000 hours.

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