Organic–Inorganic Hybrid Nanofiller Enables In situ Thermal Conductive Network toward Efficient and Stable Perovskite Solar Cells

Perovskite solar cells (PVSCs) have long faced challenges in long‐term thermal stability due to their low thermal conductivity and the volatile nature of frequently incorporated additives. Herein, we report a versatile strategy that uses organic–inorganic hybrid filler, composed of 3‐methacryloxypropyltris(trimethylsiloxy)silane (MPTMS)‐modified Al 2 O 3 nanoparticles, to construct an in situ thermal conduction network in perovskite. The surface modifier, MPTMS, of the hybrid filler has multiple functionalities in regulating the chemical interactions, perovskite crystallization, and intermolecular compatibility. Specifically, it's carbonyl moiety coordinates with Pb 2 + in perovskite to passivate defects and stabilize the α‐phase, while its hydrolyzed groups enhance Al 2 O 3 ‐perovskite compatibility for the formation of uniform thermal conductive pathways. The resultant PVSC achieves 27.05% efficiency and retains 96% of initial efficiency after 2000 h of maximum‐power‐point tracking at 65°C under illumination. This work synergistically optimizes the thermal behavior and crystallization stability in perovskite, offering a viable way to improve the thermal stability of PVSCs via complementary hybridization of organic and inorganic functional species.