Interfacial Passivation for Enhanced Moisture Stability of Perovskite Solar Cells: Ammonium or Sulfonium?

• DOI: 10.1002/admi.202400956
• Publication Date: 2025-04-29T04:54:10Z
• Authors: Oscar Telschow; Angelika Wrzesińs...; Shivam Singh; Vladimir Shilovskikh; Fulya Koc; Jianan Li; L. Andrés Guerrer...; Boris Rivkin; Bernd Plietker; Yana Vaynzof
• Keywords: Passivation; Sulfonium

Abstract Following the remarkable advances in performance of metal halide perovskite solar cells, recent research efforts have focused more on enhancing their long‐term stability. Among various factors that impact device's lifetime, humidity‐driven degradation plays an important role and can significantly lower device within hours. It is generally considered humidity‐induced proceeds via formation hydrogen bonds between water molecules nitrogen atoms widely used ammonium‐based organic cations like methylammonium (MA) formamidinium (FA). To mitigate this process, it has been suggested interfacial passivation using sulfonium – rather than ubiquitously ammonium may enhance stability against moisture. This work explores a dual modification by sulfonium‐ sulfoxonium‐based versus two commonly ones. By examining interfaces optical spectroscopy electron microscopy evaluating devices, demonstrated do not offer significant advantage over cations, with latter leading to enhanced only certain cases.