Efficiency enhancement of polymer solar cells via zwitterion doping in PEDOT:PSS hole transport layer

A novel zwitterion, 3-(N-morpholino)-2-hydroxypropanesulfonic acid (MOPSO), was applied to dope PEDOT:PSS, leading to a dramatic increase of the conductivity of PEDOT:PSS film. MOPSO:PEDOT:PSS was incorporated as hole transport layer (HTL) in BHJ-PSC devices based on P3HT:PC61BM, PCDTBT:PC71BM and PTB7:PC71BM, resulting in obvious efficiency enhancements due to the increase of Jsc, which is attributed to the conjunct factors including the increase of the photoabsorption of the photoactive layer and the improved conductivity of PEDOT:PSS HTL.196