Conjugated polymers and polyelectrolytes (CP/CPEs) exhibit excellent optoelectronic properties, which can be exploited to deliver advanced optical sensing platforms and organic solar cells. They offer the advantage of being compatible with “wet” processing technologies such as printing, providing a route to low cost thin film device fabrication. However, the nanoscale morphology of the resultant films will be highly dependent on the aggregation state of the polymer in the processing solution, which can be difficult to reproducibly control.
Our interest is in the use of solvent- and surfactant-mediation to control the self-assembly and aggregate structure of CP/CPEs in solution and subsequently deposited thin films. We use a combination of small-angle scattering (light/x-rays/neutrons), microscopy and spectroscopy to correlate the structural organization with the optoelectronic properties of the deposition solution. We then use this information to fabricate thin film devices with improved performance.
A Self-Assembly Toolbox for Thiophene-Based Conjugated Polyelectrolytes: Surfactants, Solvent and Copolymerisation, J. E. Houston,* M. Chevrier, M.-S. Appavou, S. M. King, S. Clément* and R. C. Evans*, Nanoscale, 2017, 9, 17481-17493.
Self-Assembled Conjugated Polyelectrolyte-Surfactant Complexes as Efficient Cathode Interlayer Materials for Bulk Heterojunction Organic Solar Cells, M. Chevrier, J. E. Houston, J. Kesters, N. Van den Brande, A. E. Terry, S. Richeter, A. Mehdi, O. Coulembier, P. Dubois, R. Lazzaroni, B. Van Mele, W. Maes*, R. C. Evans* and S. Clément*, J. Mater. Chem. A, 2015, 3, 23905-23916.
All-Conjugated Cationic Copolythiophene “Rod-Rod” Block Copolyelectrolytes: Synthesis, Optical Properties and Solvent-Dependent Assembly. A. Thomas, J. E. Houston, N. Van den Brande, J. De Winter, M. Chevrier, R. K. Heenan, A. Terry, S. Richeter, A. Mehdi, B. Van Mele, P. Dubois, R. Lazzaroni, P. Gerbaux, R. C. Evans* and S. Clément*, Polym. Chem., 2014, 5, 3352-3362.