Efficiency-improved organic solar cells based on plasticizer assisted soft embossed PEDOT:PSS layers

Technische Universität München, Physik-Department, Lehrstuhl für Funktionelle Materialien, James-Franck-Str. 1, 85748 Garching, Germany. .
Physical Chemistry Chemical Physics (Impact Factor: 4.49). 10/2012; 14(43):15088-98. DOI: 10.1039/c2cp42918g
Source: PubMed


Organic solar cells (OSCs) have attracted extensive attention as a promising approach for cost-effective photovoltaic devices. This study demonstrates a novel imprinting approach based on additional plasticizing, which is suited for thin polyethylenedioxythiophene:polystyrenesulphonate (PEDOT:PSS) layers. Such films are widely used as electron blocking and hole collecting intermediate layers in OSCs. Master molds with nano-scale channels are used for the temperature and pressure assisted imprinting routine and the shape of the imprinted structures is easily tunable via the plasticizer concentration. Depending on the surface topology of the PEDOT:PSS films structured poly(3-hexylthiophene) (P3HT):phenyl-C(61)-butyric acid methyl ester (PCBM) bulk heterojunction solar cells have improved power conversion efficiencies in comparison to their planar references. This effect results from enhanced optical absorption due to the resulting textured aluminum electrode and improved charge carrier extraction at the artificially structured electrodes. In addition, OSCs based on low aspect ratio PEDOT:PSS imprints show increased relative performance under oblique light incidence.

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    • "In order to induce greater light absorption in the photoactive layer, nano-patterning is often applied to the metal-oxide buffer layer, which functions as the electron extraction/transportation layer. Not only on metal-oxide buffer layer, plasticizer assistied soft embossing (PASE) structure have been applied on PEDOT:PSS hole extracting layer to improve solar cell performance17. For P3HT:PCBM solar cells based on PASE structured PEDOT:PSS layers the averaged overall power efficiency is improved by up to 18%. "
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