| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1263982 | Organic Electronics | 2013 | 9 Pages |
A solvent additive in PEDOT:PSS solution is one of many methods to improve the conductivity of the poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films. We explore a new type of the solvent additive, namely tetramethylene sulfone (TMS), for the fabrication of the PEDOT:PSS conductive layer in the ITO/PEDOT:PSS/P3HT:PCBM/TiOx/Al polymer photovoltaic cells, in comparison to a more common dimethyl sulfoxide (DMSO) solvent additive. At optimal conditions, the TMS additive at 10 wt.% has been found to enhance the conductivity of pristine PEDOT:PSS films from 0.04 S/cm up to approximately 189 S/cm, compared with the highest conductivity for the case of the DMSO additive at 15 wt.% of 117 S/cm. Possible mechanisms of this conductivity enhancement, relating to the polymer conformation and the film morphology, have been investigated by Raman spectroscopy, X-ray diffraction, atomic force microscopy, and transmission electron microscopy. The performance of the polymer photovoltaic cells fabricated with the solvent additives PEDOT:PSS films follows a similar trend to the conductivity of the films as a function of the additive concentration. The additives mainly lead to greater short circuit current density (Jsc) of the photovoltaic cells. The highest power conversion efficiency (PCE) of 2.24% of the device has been obtained with the 10 wt.% TMS additive of, compared to the PCE of 1.48% for the standard device without solvent additive.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The tetramethylene sulfone additive has been found to enhance the conductivity of pristine PEDOT:PSS films. ► The conductivity enhancements, relating to conformation and morphology, have been investigated by Raman, XRD, AFM, and TEM. ► The conductivity of PEDOT:PSS film increases from 0.04 S/cm to 188.65 S/cm for the PEDOT:PSS films produced with TMS. ► The additives mainly lead to greater short circuit current density (Jsc) of the photovoltaic cells.
