α-DTC

In this work, two new C(70) isomers, α and β bis(2-(thiophen-2-yl)ethyl)-C(70)-fullerene mono-adducts (DTC(70)), were synthesized, characterized and used as electron transporting materials (ETMs) in perovskite solar cells (PSCs). Our results show that the α isomer improves both the J(sc) and FF values of the devices, when compared to the results for the β-isomer and to those for phenyl-C(70)-butyric acid methyl ester (PC(71)BM), used as control. Devices based on α-DTC(70) achieved a power conversion efficiency (PCE) of 15.9%, which is higher than that observed with PC(71)BM (15.1%).