Reducing the cell-to-module performance gap of inorganic perovskite by anisotropically-structured hole transport materials

Abstract

All inorganic perovskites have emerged as attractive light-harvesting materials for perovskite solar cells due to their superior thermal and photostability. However, the significant performance gap between lab-scale cell and large-area module remains a major challenge for commercialization. Here, we introduced an anisotropically engineered hole transport material (HTM), which exhibited stronger interfacial adsorption and improved energy-level alignment with CsPbI3, and formed a uniform and robust hole transport layer, that enhanced both efficiency and stability. As a result, CsPbI3 based devices achieved power conversion efficiencies (PCE) of 20.0% in 0.16 cm2 single cell and 16.7% in 186 cm2 module, representing the narrowest cell-to-module PCE gap reported for inorganic PSCs. Moreover, the enhanced interfacial coupling between SF-MPA-MCz and CsPbI3 effectively suppressed thermal degradation and ion migration, thereby improving device durability. The encapsulated module maintained 80% of the initial PCE after 1500 h of damp-heat testing (i.e., in 85 °C and 85% R. H. air), and retained 80% of their initial PCE after 4000 h operation under continuous 1-sun illumination at 40 °C.