Inverted structure organic photovoltaic devices employing a low temperature solution processed WO3 anode buffer layer

Solution processing is a convenient method and also the guarantee for low cost and large-scale organic photovoltaic (OPV) production. It was recently suggested that the absorption of OPV devices can be spectrally extended by introducing ternary semiconductor blends, where a second donor with a complementary absorption spectrum is added into the active layer. In this manuscript we demonstrate the successful replacement of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) by low temperature solution processed tungsten trioxide (WO3) nanoparticles for inverted OPV devices based on either poly(3-hexylthiophene) (P3HT): phenyl-C61-butyric acid methyl ester (PCBM) or P3HT: poly[2,1,3-benzothiadiazole-4,7-diyl[4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b′]dithiophene-2,6-diyl]] (Si-PCPDTBT):PCBM active layers. These WO3 nanoparticles can serve as fully functional anode buffer layers in inverted OPV devices without further treatment, while showing comparable functionality as PEDOT:PSS layers.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Inverted organic solar cells employing solution processed WO3 anode buffer layer. ► The WO3 nanoparticles serve efficiently without any post-treatment. ► In solar cells the WO3 layer shows the similar functionality as PEDOT:PSS. ► Fill factor of >60% is obtained in the P3HT:PCBM-based inverted solar cells.