Design of SnO₂ Electron Transport Layer in Perovskite Solar Cells to Achieve 2000 h Stability Under 1 Sun Illumination and 85 °C

In order to realize both efficient and stable perovskite solar cells, designing electron transport layer (ETL) is of crucial importance withstand constant light illumination thermal stress while maintaining high charge extractability. Herein, commonly used SnO2 nanoparticle-based ETL for cells modified by ionic-salt ammonium chloride (NH4Cl) tin dihydrate (SnCl2∙2H2O) as additives, which easily fabricated simple one-step spin coating single precursor solution. With the presence these dual additives at ETL, crystallinity upper clearly enhanced. Defect analyses on devices suggest that modifications can effectively passivate trap sites reside within interfaces with carrier-transport layers. As a result, results in an improvement device stability under or condition, over 80% its initial efficiency after ≈2000 h storage elevated temperature (85 °C) ≈2400 operation 1 sun illumination.