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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Researchers social network

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

Hybrid and Organic Photo-Voltaic (HOPV 2013) - The effect of photo-oxidation on the charge carriers dynamics in P3HT : PCBM films as monitored by transient absorption spectroscopy

The effect of photo-oxidation on the charge carriers dynamics in P3HT : PCBM films as monitored by transient absorption spectroscopy

T. Sauermann2, H.-J. Egelhaaf2, S. Karuthedath1, L. Lüer1, R. Wannemacher1, C. Brabec3

Optical Spectroscopy and Microscopy of Nanostructured Materials, IMDEA Nanociencia, C/ Faraday, 9, 28049 Cantoblanco (Madrid), Spain.

Belectric OPV GmbH , Landgrabenstr. 94, 90443 Nürnberg, Germany.

Materials for Electronics and Energy Technology (MEET), Friedrich-Alexander-Universität Erlangen-Nürnberg, Werkstoffwissenschaften Martensstrasse 7 D-91058 Erlangen, Germany

Poster Presentation at Hybrid and Organic Photo-Voltaic (HOPV 2013) Conference  in Seville, Spain, [May 2013]:


The effect of chemical degradation of the active layer of organic solar cells on the performance of the devices is still poorly understood. This study therefore attempts to shed light on how light-induced oxidation of a model polymer influences charge carrier generation and recombination in the bulk heterojunction with the most commonly used fullerene. To this end, blend films of poly(3-hexylthiophene)/[6,6]-phenyl C 61-butyric acid methyl ester (P3HT/PCBM) were degraded under AM 1.5 illumination in dry synthetic air, focusing on degradation levels which are relevant for the operation of solar cells. The extent of degradation was quantified by the UV/vis-absorbance loss of P3HT. The change of the charge carrier dynamics in the P3HT phase during degradation was measured by µs-transient absorption spectroscopy. The concentration of generated charge carriers is not influenced noticeably by oxygen introduced defects. However, the recombination kinetics of the charge carriers changes significantly. In undegraded films, the recombination kinetics is of second order, with charge carrier lifetimes of around ten microseconds at solar intensities. Upon degradation, the recombination rate of the polarons is reduced significantly, the kinetics assuming power-law character. Even at minor damage (2% ground state absorption loss of P3HT) around 10% of the charge carriers are still present after 1ms. We rationalize these effects by invoking oxygen-induced traps that reduce the effective mobility of the photo-generated charge carriers.

Poster Sevilla