Polymer‐Regulated SnO<sub>2</sub> Composites Electron Transport Layer for High‐Efficiency n–i–p Perovskite Solar Cells
Zhenhua Xu, Xinming Zhou, Xiaohui Li, Putao Zhang
Abstract
SnO 2 electron transport layer (ETL) plays a critical role in constructing a planar perovskite solar device. Improving SnO 2 ETL properties and understanding of interfacial energy loss are key factors to fabricate highly efficient and reproducible perovskite solar cells (PSCs). Herein, a nonionic surfactant, polyethylene oxide‐polypropylene oxide‐polyethylene oxide (P123), is introduced to suppress the aggregation of SnO 2 nanoparticles for a uniform SnO 2 ETL. The P123 polymer can maintain the SnO 2 colloidal size around 10 nm over 72 h at 35 °C and thus promote the dispersion of nanoparticles in SnO 2 precursor. By spin coating P123‐doped SnO 2 (SnO 2 ‐P) colloid, the compactness and uniformity of SnO 2 layer are improved significantly. Correspondingly, SnO 2 ‐P‐based devices demonstrate a champion efficiency with enhanced open‐circuit voltage ( V OC ) of 1.162 V. Due to the SnO 2 /perovskite interface binding interaction, the devices gain a high long‐term stability, retaining 85% of their initial performance after 1000 h storage in air. Equally important, the polymer‐regulated ETL allows a competitive efficiency of 17.44% with active area of 1.00 cm 2 , exhibiting much potential for large‐scale solar devices. This ETL modification approach provides a new and simple route to improve the quality of SnO 2 colloid solution for fabricating efficient perovskite devices.