The photovoltaic community is currently experiencing the revolution of the solar cells based on perovskite materials. Since the first reports based on a solid hole-transporting layer appeared, a great variety of organic molecules have been employed as electron or hole-selective contacts in regular and/or inverted perovskite-based solar cells (PSCs) (Figure 1 A and C, respectively). Fullerene and their derivatives are playing a very important role as electron-selective contact (ESC) in inverted solar cells as well as in self-assembled monolayers of fullerene derivatives on TiO2 in regular devices. Moreover, the interest of fullerenes in PSCs has been increased by the recent report of Snaith’s group, which describes the successful incorporation of [60]fullerene instead of the usual TiO2 as ESC in regular PSCs architectures (Figure 1B).

In the present comunication, careful photovoltaic studies following a well-described experimental protocol have been carried out with PSC fabricated with [70]fullerene,  [60]fullerene and [60]fullerene derivatives as Electron Transport Material in regular perovskite solar cell architecture, in order to study their suitability as ETM for PSC. The obtained results indicate that the use of these materials as ET materials in PSC allow the obtention of highly efficient devices (≥10%), due to the introduction of the "fullerene saturation approach".