Multifunctional Pyrene‐Carbazole Integration as Flexible‐Skeletonized Hole Contact for Stable Inverted Perovskite Solar Cells

ABSTRACT Pyrene has demonstrated outstanding potential in perovskite photovoltaics, both as a building block in self‐assembled monolayers (SAMs) and as a core component in traditional hole‐transport materials (HTMs). Its rigid planar structure and strong π‐conjugation enhance charge transport, molecular order, and interfacial stability. However, current designs remain constrained to simple substitution strategies, limiting further performance gains. To address this, we integrate pyrene with high‐mobility carbazole units through two tailored architectures: a fused rigid system (4PAPyCz) and a flexibly linked twisted system (Py‐4PACz). While the rigid design leads to excessive aggregation, the flexible Py‐4PACz optimizes molecular orientation and allows pyrene to function as an interfacial strain buffer, significantly reducing nonradiative loss. As a result, inverted perovskite solar cells based on Py‐4PACz achieve over 25% efficiency and exceptional operational stability, retaining >91.2% efficiency after 700 h of maximum power point tracking, and >90% following the stringent ISOS‐L‐3 damp‐heat protocol. This work provides a rational design strategy to unlock the multifunctional potential of pyrene‐based materials for efficient and stable photovoltaics.