Phosphonium‐based polythiophene conjugated polyelectrolytes with different surfactant counterions: thermal properties, self‐assembly and photovoltaic performances

DOI: 10.1002/pi.6088

Authors: Michèle Chevrier (ICGM, Univ. Montpellier, CNRS) , Jurgen Kesters (UHasselt – Hasselt University) , Judith E. Houston (Jülich Centre for Neutron Science (JCNS) at the Heinz Maier‐Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH) , Niko Van Den Brande (Vrije Universiteit Brussel (VUB)) , Sylvain Chambon (Univ. Bordeaux, IMS, CNRS) , Sébastien Richeter (ICGM, Univ. Montpellier, CNRS) , Bruno Van Mele (Vrije Universiteit Brussel (VUB)) , Thomas Arnold (Diamond Light Source; European Spallation Source ERIC; University of Bath; ISIS Neutron and Muon Source) , Ahmad Mehdi (ICGM, Univ. Montpellier, CNRS) , Roberto Lazzaroni (University of Mons ‐ UMONS) , Philippe Dubois (University of Mons ‐ UMONS) , Rachel C. Evans (University of Cambridge) , Wouter Maes (UHasselt – Hasselt University, Institute for Materials Research (IMO)) , Sébastien Clément (ICGM, Univ. Montpellier, CNRS)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Polymer International

State: Published (Approved)
Published: July 2020
Diamond Proposal Number(s): 13868

Abstract: Phosphonium‐based polythiophene conjugated polyelectrolytes (CPEs) with three different counterions (dodecylsulfate (DS), octylsulfate (OS) and perfluorooctylsulfonate (PFOS)) are synthesized to determine how the nature of the counterion affects the thermal properties, the self‐assembly in thin films and the performance as cathode interfacial layer in polymer solar cells (PSCs). The counterion has a significant effect on the thermal properties of the CPEs, affecting both their glass transition and crystalline behavior. Grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) studies also indicate that changing the nature of the counterion influences the microstructural organization in thin films (face‐on vs . edge‐on orientation). The affinity of the CPEs with the underlying photoactive layer in PSCs is highly correlated with the counterion species. Finally, in addition to an increase of the power conversion efficiency of ~15% when using these CPEs as cathode interfacial layers in PSCs, a higher device stability is noted, as compared to a reference device with a calcium interlayer.

Journal Keywords: Conjugated polyelectrolytes; surfactant counteranion; self‐assembly; thin films; cathode interlayers; organic solar cells

Subject Areas: Materials, Physics


Instruments: I07-Surface & interface diffraction