Improved Carrier Collection and Hot Electron Extraction Across Perovskite, C60, and TiO2 Interfaces

The use of C-60 as an interfacial layer between TiO2 and methylammonium lead iodide perovskite is probed to reduce the current-voltage hysteresis in perovskite solar cells (PSCs) and, in turn, to impact the interfacial carrier injection and recombination processes that limit solar cell efficiencies. Detailed kinetic analyses across different time scales, that is, from the femtoseconds to the seconds, reveal that the charge carrier lifetimes as well as the charge injection and charge recombination dynamics depend largely on the presence or absence of C-60. In addition, we corroborate that C-60 is applicable in hot carrier PSCs as it is capable of extracting hot carriers generated throughout the early time scales following photoexcitation.