About Establis

Earth receives enough sunlight in one hour to satisfy all human needs in a year. Using solar energy will reduce harmful CO2 emissions and resolve the forthcoming energy deficit. The market for stable, mass-produced Organic Solar Cells is estimated at one billion Euros by 2016.

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ESTABLIS will train a team of 11 PhDs and 4 Postdocs to become the scientific leaders in industry and academia. ESTABLIS Fellows will excel.

Research on organic solar cells

Complementarity is at the heart of Establis. To develop Organic Solar Cells requires a concerted combination of physical, synthetic and modelling capabilities. Establis members are working together–across preconceived scientific boundaries–to accelerate the production of Organic Solar Cells.

Partnerships & collaborations

Our Industrial Partners and Associate Partners ensure that the training and technology is economically feasible.

EU support

The EEC is constructively investing more than 3.9 M€ in Establis to train, research and collaborate at the highest international level and ensure our energy platform for the 21st century.

Scientific results

ECME 2013 - Clevios™ HTL Solar 2: A new solvent based PEDOT : PSS for organic photovoltaics

Clevios™ HTL Solar 2: A new solvent based PEDOT : PSS for organic photovoltaics

Stefan Schumann*, Andreas Elschner,Detlef Gaiser, Wilfried Lövenich
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Heraeus Precious Metals GmbH & Co. KG, Conductive Polymers Division (Clevios) Chempark Leverkusen/Gebäude B 202, D-51368 Leverkusen, Germany


There has been recent interest in solution processed inverted device architecture bulk heterojunction (BHJ) organic photovoltaic devices (OPV) due to several advantages over regular device architectures, including improved operational device life times, ease of device fabrication and also the great potential for low cost manufacturing1.
Amongst many applications Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOTRazzSS) is a well-established hole-transport material in OPV devices due to its tailored workfunction for good contacts and solution processability. When applied in inverted architectures the interface between photo-active layer and PEDOTRazzSS was identified as critical for device stability due to layer delamination as one contributor to device degradation2.
In this study the focus is on this particular interface and the PEDOTRazzSS dispersion development to improve the required layer adhesion for enhanced stability including PEDOTRazzSS formulation development and annealing processes. To evaluate the effect different adhesion  haracterisation techniques are developed and existing ones tested to establish a reliable control system allowing a comparison to reference
systems. The techniques involve different standard tape tests but also spectroscopic measurements. Complementary to an enhanced adhesion the development targets PEDOTRazzSS dispersions with good wettability and film formation properties on nonpolar surfaces of photo-active materials which are required to allow device fabrication.
The PEDOTRazzSS formulations as well as specific treatments and annealing are then tested in inverted OPV devices based on the model system ITO/ ZnO/Poly(3-hexylthiophene): Phenyl-C61-butyric acid methyl ester (P3HTRazzCBM)/PEDOTRazzSS/Ag to translate this added functionality into the device application. In afinal step long-term device stability tests performed allow evaluating the effects of the different adhesion improvement solutions developed and show the impact on the important operational device stability.
Further the studies enable to develop a deeper understanding of this structure-function relationship influencing the interface as well as the layer adhesion and to determine the important parameters for an enhanced device life-time.

The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2011 under grant agreement ESTABLIS n° 290022).

1. T. T. Larsen-Olsen et al, Adv. Ener. Mater. 2, 9 (2012)
2. M. Jørgensen et al, Adv. Mater. 24, 5 (2012)

Clevios™ HTL Solar 2: A new solvent based PEDOT:PSS for organic photovoltaics