Fluorinated Sulfonated Poly(ether sulfone)-Based Poly(3,4-ethylenedioxythiophene) Dispersion: A Hole Transport Layer Material in Organic Solar Cells

Here the synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) aqueous dispersion using sulfonated poly(ether sulfone) (SPES) with hydrophobic fluorinated groups to improve the weather and water stability of the conductive film is reported. The conductivity and surface morphology of the fabricated PEDOT:SPES conductive thin films are investigated. The PEDOT:SPES film after the N,N-dimethylformamide (DMF) treatment showed a 200 times increase in the conductivity and the transmittance is over 96.5%. Raman spectroscopy indicates conformational changes in PEDOT chains due to the solvent treatment. The PEDOT:SPES film shows better water and weather stability performance in terms of dimensional stability in comparison to the commercial PEDOT:poly(styrene sulfonic acid) (PSS). Further, the organic solar cells performance is tested using PEDOT:SPES as hole transport layer and poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C-71-butyric acid methyl ester (PC71BM) as active material. The PEDOT:SPES achieves a good power conversion efficiency (=3.36%), comparable with the conventional PEDOT:PSS (AI 4083).