Giordano, FabrizioAbate, AntonioBaena, Juan Pablo CorreaSaliba, MichaelMatsui, TaisukeIm, Sang HyukZakeeruddin, Shaik M.Nazeeruddin, Mohammad KhajaHagfeldt, AndersGraetzel, Michael2016-04-012016-04-012016-04-012016-01-1310.1038/ncomms10379https://infoscience.epfl.ch/handle/20.500.14299/125497WOS:000369022100016Perovskite solar cells are one of the most promising photovoltaic technologies with their extraordinary progress in efficiency and the simple processes required to produce them. However, the frequent presence of a pronounced hysteresis in the current voltage characteristic of these devices arises concerns on the intrinsic stability of organo-metal halides, challenging the reliability of technology itself. Here, we show that n-doping of mesoporous TiO2 is accomplished by facile post treatment of the films with lithium salts. We demonstrate that the Li-doped TiO2 electrodes exhibit superior electronic properties, by reducing electronic trap states enabling faster electron transport. Perovskite solar cells prepared using the Li-doped films as scaffold to host the CH3NH3PbI3 light harvester produce substantially higher performances compared with undoped electrodes, improving the power conversion efficiency from 17 to over 19% with negligible hysteretic behaviour (lower than 0.3%).text::journal::journal article::research article