Universal nanoparticle wetting agent for upscaling perovskite solar cells

Moritz Schultes, Nadja Giesbrecht, Johannes Küffner, Erik Ahlswede, Pablo Docampo, Thomas Bein, Michael Powalla

Research output: Contribution to journalArticleResearchpeer-review

24 Citations (Scopus)


Solution-processed perovskite solar cells reach efficiencies over 23% on lab-scale. However, a reproducible transfer of these established processes to upscaling techniques or different substrate surfaces requires a highly controllable perovskite film formation. Especially, hydrophobic surfaces cause severe dewetting issues. Such surfaces are particularly crucial for the so-called standard n-i-p cell architecture when fullerene-based electron transport layers are employed underneath perovskite absorber films. In this work, a unique and universally applicable method was developed based on the deposition of size-controlled Al 2 O 3 or SiO 2 nanoparticles. By enhancing the surface energy, they act as a universal wetting agent. This allows perovskite precursor solutions to be spread perfectly over various substrates including problematic hydrophobic Si-wafers or fullerene self-assembled monolayers (C 60 -SAMs). Moreover, the results show that the perovskite morphology, solar cell performance, and reproducibility benefit from the presence of the nanoparticles at the interface. When applied to 144 cm 2 C 60 -SAM-coated substrates, homogenous coverage can be realized via spin coating resulting in average efficiencies of 16% (maximum 18%) on individualized cells with 0.1 cm 2 active area. Modules in the same setup reached maximum efficiencies of 11 and 7% on 2.8 and 23.65 cm 2 aperture areas, respectively.

Original languageEnglish
Pages (from-to)12948-12957
Number of pages10
JournalACS Applied Materials & Interfaces
Issue number13
Publication statusPublished - 12 Mar 2019
Externally publishedYes


  • contact angles
  • nanoparticles
  • perovskites
  • surface modification
  • upscaling
  • wetting

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