N-type polymers as electron extraction layers in hybrid perovskite solar cells with improved ambient stability

Abstract

We studied three n-type polymers of the naphthalenediimide-bithiophene family as electron extraction layers (EELs) in hybrid perovskite solar cells. The recombination mechanism in these devices is found to be heavily influenced by the EEL transport properties. The maximum efficiency of the devices using the n-type polymers EELs did not exceed substantially that of the devices using PC60BM (about 11%), while a substantial improvement in their ambient stability (87% of the initial value after 270 minutes) compared to that using PC60BM (3.5% of the initial value after 270 minutes) was detected.