Enhanced Efficiency and Stability of Inverted Perovskite Solar Cells Using Highly Crystalline SnO₂Nanocrystals as the Robust Electron-Transporting Layer

An experiment was conducted to successfully exploit the solution-processed SnO₂ nanocrystals (NCs) to serve as an efficient ETL in the inverted thin-film perovskite solar cells (PVSC). The SnO₂ NCs were prepared though the typical solgel hydrolysis method. The hydrothermal method was adopted to prepare the SnO₂ NCs (denoted as hydrothermal SnO₂) since it has been reported to facilitate the growth of highly crystalline SnO₂ NCs under high temperature (200°C) and pressure in an autoclave. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were then conducted to characterize the morphology and crystallinity of the prepared SnO₂ NCs. a compact and stable protecting layer for device is spontaneously formed to remarkably enhance the ambient stability of the derived PVSC. As shown, over 90% of its initial PCE can be retained after 30 d storage in ambient with 2 ETL not only provides a simple way to improve the performance and stability of PVSCs but also shows the great merits in future development of efficient interconnecting layers for perovskite-based tandem cells.