Enhancing the efficiency of planar heterojunction perovskite solar cells via interfacial engineering with 3-aminopropyl trimethoxy silane hydrolysate

The interfacial compatibility between compact TiO₂ and perovskite layers is critical for the performance of planar heterojunction perovskite solar cells (PSCs). A compact TiO₂ film employed as an electron-transport layer (ETL) was modified using 3-aminopropyl trimethoxy silane (APMS) hydrolysate. The power conversion efficiency (PCE) of PSCs composed of an APMS-hydrolysate-modified TiO₂ layer increased from 13.45 to 15.79%, which was associated with a significant enhancement in the fill factor (FF) from 62.23 to 68.04%. The results indicate that APMS hydrolysate can enhance the wettability of γ-butyrolactone (GBL) on the TiO₂ surface, form a perfect CH₃NH₃PbI₃ film, and increase the recombination resistance at the interface. This work demonstrates a simple but efficient method to improve the TiO₂/perovskite interface that can be greatly beneficial for developing high-performance PSCs.