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Rogowski, Rafal
Publications (2 of 2) Show all publications
Heidkamp, H., van Stam, J., Carlsson, G., Moons, E., Dzwilewski, A. & Rogowski, R. (2011). Morphology of P3HT and PCBM blends in thin films obtained with different deposition methods. In: : . Paper presented at 25th European Colloid and Interface Society Conference, Berlin, Germany, September 4-9, 2011.
Open this publication in new window or tab >>Morphology of P3HT and PCBM blends in thin films obtained with different deposition methods
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2011 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Patterns and structures, formed when a semiconducting polymer blend in solution is subject to controlled evaporation, have been of great interest due to their influence on the performance of organic devices. By controlling the processes of pattern formation, function properties of organic semiconductor structures can be tailored, allowing for facile manufacturing of the active layers in organic devices, e.g. solar cells.

By analyzing the morphologies of polymer blends resulting from different deposition methods, a deeper insight into the pattern formation process can be acquired. In this study, we have analyzed the morphology of blends of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) formed upon solvent evaporation. We used the following deposition methods: dip-coating, droplet evaporation within a constrained geometry and drop-casting. Dip-coated films revealed various types of morphology depending on the coating speed. At low coating speeds, where evaporation is the dominant factor, well-ordered patterns were obtained. When increasing the coating speed, viscous forces become dominant over evaporation yielding optically homogenous films [2]. Morphologically similar structures to those observed at low coating speeds, were also obtained with spatially constrained droplets. The blend morphologies were analyzed with polarized, fluorescence and atomic force microscopy [1].

References:

[1] C. M. Björström Svanström, J. Rysz, A. Bernasik, A. Budkowski, F. Zhang, O. Inganäs, M. R. Andersson, K. O. Magnusson, J. J. Benson-Smith, J. Nelson, and E. Moons, Adv. Mat. 21, 4398-4403 (2009)

[2] R. Z. Rogowski and A. A. Darhuber, Langmuir 26, 11485-93 (2010)

National Category
Physical Sciences
Research subject
Chemistry
Identifiers
urn:nbn:se:kau:diva-14564 (URN)
Conference
25th European Colloid and Interface Society Conference, Berlin, Germany, September 4-9, 2011
Available from: 2012-08-24 Created: 2012-08-24 Last updated: 2019-05-20Bibliographically approved
Heidkamp, H., Rogowski, R., Dzwilewski, A., van Stam, J., Moons, E. & Carlsson, G. (2011). Morphology of polymer blends in films made by dip-coating. Paper presented at Soft and hard materials : A symposium on surface and materials chemistry. Lund, Sweden, October 25-27, 2011.
Open this publication in new window or tab >>Morphology of polymer blends in films made by dip-coating
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2011 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Thin spincoated polymer films are used in various applications and there has been anincreasing demand to understand and get precise control over the film formation process. One of the most exciting applications is organic solar cells which have an active layer made of a polymer based blend. The film morphology has a strong effect on the efficiency of solar cells and therefore it is crucial to understand the film formation process in order to tailor thedesired morphology [1].

In this study we are combining and comparing results from three different deposition processes: drop-casting, sphere-on-flat arrangement and dip-coating. We are using dip-coating to produce thin films of polymer blends with different morphologies under controlled conditions. The main goal is to gain a deeper insight into the processes that occur while solvent evaporates and to understand why certain structures are formed.

Drop-casting allows for little control of the structure formation. In the sphere-on-flat arrangement a droplet of a solution is constrained between a half-sphere and the substrate, which provides more controllable conditions for the deposition process. For more precise control, dip-coating can be used, where a substrate is withdrawn from a solution at a constant speed.

In this study we have used the polymer poly(3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) dissolved in toluene. These components are the model system for studies on organic solar cells [1]. The dip-coated films show a wide variety of morphologies depending on the coating speed. This dependence can be rationalized by the different mechanisms occurring at low and high speeds: At low speeds, evaporation is dominant, [2] resulting in well ordered patterns. At high speeds, viscous forces become dominant, [2] yielding optically homogeneous films.

[1] G. Dennler, M. C. Scharber, C. J. Brabec, Adv. Mat. 21, 1323-1338 (2009)

[2] R. Z. Rogowski and A. A. Darhuber, Langmuir 26, 11485-93 (2010)

National Category
Physical Chemistry
Research subject
Chemistry; Physics
Identifiers
urn:nbn:se:kau:diva-12329 (URN)
Conference
Soft and hard materials : A symposium on surface and materials chemistry. Lund, Sweden, October 25-27, 2011
Available from: 2012-03-16 Created: 2012-03-16 Last updated: 2017-12-06Bibliographically approved
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