Degradation mechanism of hybrid tin-based perovskite solar cells and the critical role of tin (IV) iodide

Luis Lanzetta, Thomas Webb, Nourdine Zibouche, Xinxing Liang, Dong Ding, Ganghong Min, Robert J.E. Westbrook, Benedetta Gaggio, Thomas J. Macdonald, M. Saiful Islam, Saif A. Haque

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Tin perovskites have emerged as promising alternatives to toxic lead perovskites in next-generation photovoltaics, but their poor environmental stability remains an obstacle towards more competitive performances. Therefore, a full understanding of their decomposition processes is needed to address these stability issues. Herein, we elucidate the degradation mechanism of 2D/3D tin perovskite films based on (PEA)0.2(FA)0.8SnI3 (where PEA is phenylethylammonium and FA is formamidinium). We show that SnI4, a product of the oxygen-induced degradation of tin perovskite, quickly evolves into iodine via the combined action of moisture and oxygen. We identify iodine as a highly aggressive species that can further oxidise the perovskite to more SnI4, establishing a cyclic degradation mechanism. Perovskite stability is then observed to strongly depend on the hole transport layer chosen as the substrate, which is exploited to tackle film degradation. These key insights will enable the future design and optimisation of stable tin-based perovskite optoelectronics.

Original languageEnglish
Article number2853
JournalNature Communications
Volume12
Issue number1
Early online date14 May 2021
DOIs
Publication statusE-pub ahead of print - 14 May 2021

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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