Additive enhanced passivation and lead immobilization of waste expandable polystyrene for perovskite photovoltaics

Abstract

Every year, millions of tons of expandable polystyrene (EPS) are released into the environment, posing significant environmental pressure due to its slow natural decomposition that takes hundreds of years. Current recycling methods for EPS include organic solvent dissolution and recycling, composite material preparation, and building decoration. However, these methods are costly and have low utilization value. In this study, we propose an innovative approach by incorporating waste EPS into the assembly process of printable mesoscopic perovskite solar cells (p-MPSCs). Our findings reveal that EPS can not only utilize its uncoordinated Pb2+ coordination through the large π bond of the benzene ring, but also the functional groups of C=O and C≡N in its additives, benzophenone peroxide and azobisisobutyronitrile, respectively, play an efficient role in passivating lead defects. Furthermore, EPS effectively acts as a moisture barrier, preventing moisture from entering the interior of the device. This significantly improves device stability and immobilizes lead ions, preventing lead leakage. Our approach not only provides an efficient and environmentally friendly method to recycle EPS, but also offers new solutions to address fundamental scientific challenges in perovskite solar cells, such as lead leakage and stability issues.