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

6th international Conference on Hybrid Inorganic-Organic Photovoltaics (HOPV14) - Development of a Testing Adhesion/Cohesion Technique in OPV Devices

Development of a Testing Adhesion/Cohesion Technique in OPV Devices 

A.Gregori1, S. Schumann2, C. Dagron-Lartigau1, A. Allal*1, Roger C. Hiorns3

 

 

1 EPCP, IPREM (UMR-5254), Université de Pau et des Pays de l’Adour, 2 avenue du Président Angot, 64053 Pau, Cedex, France

2 Heraeus Precious Metals GmbH & Co. KG, Electronic Materials Division, Chempark Leverkusen/Gebäude B 202, D-51368 Leverkusen, Germany

3 CNRS, EPCP, IPREM (UMR-5254), 2 avenue du Président Angot, 64053 Pau,          Cedex, France

 

Abstract: Organic photovoltaic devices (OPVs) are one of the most promising applications of organic semiconductors due to their compatibility with flexible plastic substrates resulting in light weight, inexpensive and decorative products. Inverted device architecture bulk heterojunction (BHJ) OPVs offer several advantages over regular device architectures including improvement of operational device lifetimes, ease of device fabrication and lower manufacturing cost. While the electrical failure mechanisms in OPVs have been thoroughly investigated, little is known about their mechanical stability, which is important and critical to ensure long term reliability. The characteristic thin films stresses of each layer present in OPVs, in combination with other possible fabrication, handling and operational stresses, provide the mechanical driving force for delamination of weak interfaces and even their decohesion, leading to a loss of device integrity and performance [1]. In this study, we developed a technique to probe for weak layers or interfaces in inverted polymer:fullerene solar cells, establishing a new set-up for the so-called probe tack [2]. It is based on a well-established technique used to study adhesion properties of soft polymers on hard surfaces. The new technique consists of adding an adhesive layer to the top of the sample of interest, followed by a very controlled pulling in perpendicular to the surface at set speed ultimately leading to a break at its weakest point in the device layer structure. The created surface is then characterized by contact angle measurement, optical microscopy and AFM.

            As a model device structure for this study an inverted geometry OPV device has been chosen in which the organic layers have been deposed by doctor blading and spin-coating. The choice of the adhesive, the contact time and the pressure before pulling, the probe area and the pulling speed have been thoroughly evaluated, leading to the best conditions to perform the measurements.

 

[1] M. Jorgensen et al., Adv. Mater. 24, 5 (2012)

[2] C. Creton and P. Fabre, Adhesion Science and Engineering I, Elsevier (2002).

 

HOPV14 Gregori Gratzel Lausanne Establis