Interfacial Charge Modulation in Laminated Photovoltaic Backsheet‐Encapsulant Nanocomposites for Enhanced Dielectric Performance

ABSTRACT Photovoltaic (PV) technology plays a pivotal role in the global transition toward sustainable energy. With the increasing deployment of PV systems, polymeric materials used in PV modules can be exposed to various environmental stresses during operation, which may induce microstructural defects and interfacial degradation. Such degradation processes can result in local electric field distortion within polymeric materials, promoting charge accumulation and accelerating electrical aging, which may ultimately affect the reliability of PV modules. Enhancing the charge dissipation capability and breakdown strength of polymers is critical for improving the electrical reliability of PV systems. Here, polyethylene terephthalate (PET) films are modified with TiO 2 nanoparticles to regulate their charge trapping and transport characteristics. The incorporation of TiO 2 nanoparticles effectively reduces the initial surface potential and accelerates charge decay. Moreover, the PET/TiO 2 nanocomposites are laminated with a polyolefin elastomer (POE) encapsulant to construct a multilayer dielectric structure. The results reveal that the backsheet‐encapsulant interface modifies charge redistribution and relaxation processes, while TiO 2 ‐induced trap regulation further improves interfacial charge dissipation. This study provides insights into the design of polymeric materials and the optimization of interfacial performance in PV systems.