Solution-processed ZnO/MoS2 quantum dots electron extraction layer for high performance inverted organic photovoltaics

The electron extraction layer (EEL) plays a pivotal role in realizing high performance organic photovoltaics (OPVs). In this work, we report the effort to develop high-efficiency inverted OPVs with solution-processed ZnO/MoS2 quantum dots (QDs) EEL. The employ of MoS2 QDs helps to suppress the exciton quenching by passivating the ZnO surface defects. It is shown that ZnO/MoS2 EEL enables promoted electron extraction and suppressed charge recombination properties. A blend of poly(3-hexylthiophene-2,5-diyl) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) was applied as the active layer. The ZnO/MoS2-based OPVs demonstrate superior photovoltaic performance with a champion power conversion efficiency (PCE) of 3.83%, which is >17.5% higher than that of the pristine ZnO-based device (~3.26%). It is shown that the use of a blend ZnO/MoS2 QDs EEL offers an effective approach to obtain high performance optoelectronic devices.