Two‐Dimensional Surface Passivation with Distinct Cations Enabling High Efficiency and Mechanical Durability in Flexible Perovskite Solar Cells

• DOI: 10.1002/cssc.202500232
• Publication Date: 2025-04-10T15:52:03Z
• Authors: Nopporn Rujisamphan; Kay Thi Soe; Pairot Moontragoon; Annafi Ado Yaro; Ekkaphop Ketsombun; Ratchadaporn Supr...; Dian Luo; Zhi‐Hao Huang; Shun‐Wei Liu; Thidarat Supasai
• Keywords: Passivation; Polyethylene naphthalate

Recent advancements in flexible perovskite solar cells (f‐PSCs) have significantly improved power conversion efficiency (PCE) and mechanical durability, particularly when using a polyethylene naphthalate (PEN) substrate. In this study, we investigate the effects of two‐dimensional (2D) organic surface treatments—including phenylethylammonium iodide (PEAI), 5‐ammonium valeric acid (5‐AVAI), butylammonium (BAI)—on photovoltaic performance properties f‐PSCs. Our findings reveal that radiative voltage losses near band edge were minimal for 2D‐BAI (0.032 V) 2D‐PEAI (0.027 but higher 2D‐5AVAI (0.136 V). After treatment, average Young’s modulus increased to 0.48 GPa, reaching maximum 2 reinforcing resilience layer. Consequently, 2D‐BAI‐treated f‐PSCs achieved PCE 19.81% while maintaining structural integrity after 10,000 bending cycles. This study underscores effectiveness 2D treatments simultaneously enhancing both device offering valuable insights development robust electronic devices.