Hole-transporting layer-free inverted planar mixed lead-tin perovskite-based solar cells

Abstract

Mixed lead-tin (Pb-Sn) perovskites present a promising strategy to extend the light-harvesting range of perovskite-based solar cells (PSCs). The use of electrontransporting layer or hole-transporting layer (HTL) is critical to achieve high device efficiency. This strategy, however, requires tedious layer-by-layer fabrication as well as high-temperature annealing for certain oxides. In this work, we fabricated HTL-free planar FAPb0.5Sn0.5I3 PSCs with the highest efficiency of 7.94%. High shortcircuit current density of 23.13 mA/cm2 was attained, indicating effective charge extraction at the ITO/FAPb0.5Sn0.5I3 interface. This finding provides an alternative strategy to simplify the manufacture of single-junction or tandem PSCs.