A MoSe2 quantum dot modified hole extraction layer enables binary organic solar cells with improved efficiency and stability

In this paper, we demonstrate a solution-processed MoSe2 quantum dots/PEDOT:PSS bilayer hole extraction layer (HEL) for non-fullerene organic solar cells (OSCs). It is found that the introduction of MoSe2 QDs can alter the work function and phase separation of PEDOT:PSS, thus affecting the morphology of the active layer and improving the performance of OSCs. The MoSe2 QDs/PEDOT:PSS bilayer HEL can improve the fill factor (FF), short-circuit current density (Jsc) and power conversion efficiency (PCE) of OSCs based on different active layers. The best PCE of up to 17.08% was achieved based on a recently reported active layer binary system named SZ2:N3, which is among the highest reported values to date for OSCs using 2D materials as an interface modifier. Our study indicates that this simple and solution-processed MoSe2 QDs/PEDOT:PSS bilayer thin film could be a potential alternative HEL to the commonly used PEDOT:PSS conducting polymers.