Bio-Based Encapsulation Materials Enabling Recyclable and Stable Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) are considered promising next-generation photovoltaic technology due to their high power conversion efficiency and cost-effective manufacturing. However, their practical application is hindered by the lack of suitable encapsulation materials that protect against environmental degradation while maintaining compatibility with the chemical and thermal fragility of metal halide perovskites. Conventional encapsulation materials, such as ethylene-vinyl acetate (EVA) copolymer and polyolefin elastomer (POE) films, rely on high processing temperatures (<140 °C) and reactive additives, which can damage PSCs during encapsulation. Developing environmentally friendly, low-temperature encapsulation materials tailored to PSCs is therefore critical to advancing their industrialization. Here, we present a bio-based fluorinated polyether ester (PTFF) polymer film as a recyclable and nondestructive encapsulation solution for PSCs. PTFF, synthesized mainly from biomass-derived monomers, achieves additive-free adhesion through noncovalent interactions and features a tunable glass transition temperature (< 80 °C) for low-temperature hot-pressing. Encapsulated PSCs demonstrate excellent thermal and moisture stability, retaining >80% efficiency after 600 hours under damp heat conditions (85 °C, RH = 85%). Moreover, PTFF is easily recyclable via simple physical delamination methods, maintaining its adhesion performance after recovery. This work highlights a sustainable encapsulation strategy tailored to PSCs, addressing their unique stability and environmental requirements, and provides a pathway toward scalable and sustainable photovoltaic module production.