Microstructure and Optoelectronic Properties of P3HT-b-P4VP/PCBM Blends: Impact of PCBM on the Copolymer Self-Assembly

Véronique Gernigon (1) , Patrick Leveque (2) , Fanny Richard (3) , Nicolas Leclerc (3) , Cyril Brochon (4, 5) , Christoph Braun (6) , Sabine Ludwigs (6) , Denis V. Anokhin (7) , Dimitri A. Ivanov (7) , Georges Hadziioannou (4, 5) , Thomas Heiser (2)

1 Institut d'électronique du solide et des systèmes (Strasbourg)
2 InESS - Institut d'Electronique du Solide et des Systèmes
3 Ecole nationale supérieure de chimie, polymères et materiaux de strasbourg (ECPM)
4 LCPO - Laboratoire de Chimie des Polymères Organiques
5 Team 4 LCPO : Polymer Materials for Electronic, Energy, Information and Communication Technologies
6 Univ Stuttgart, Inst Polymerchem
7 IS2M - Institut de Science des Matériaux de Mulhouse

Block copolymers have been widely investigated over the past decades for their ability to microphase separate into well-defined nanostructured thin films with tailored physical properties. The aim of the present study is to investigate the thin film properties of rod coil block copolymer/phenyl-C-61-butyric acid methyl ester (PCBM) blends as a function of the blend weight ratio, using a copolymer which is based on a poly(3-hexylthiophene) (P3HT) rod block and poly(4-vinylpyridine) (P4VP) coil block. Atomic force microscopy, transmission electron microscopy and grazing incidence X-ray diffraction analysis are used to study the influence of PCBM on the copolymer self-assembling. UV-visible absorption and photoluminescence spectroscopies as well as field-effect mobility measurements are performed in order to get further insight into the blend optoelectronic properties. It is found that the block copolymer phase-separated morphology and charge carrier mobilities strongly depend on the PCBM loading and thermal annealing. In particular, the results point out that PCBM enhances the block copolymer microphase separation within a narrow range of the polymer:PCBM weight ratio. In addition, clear evidence for PCBM accumulation within the P4VP domains is found by monitoring the P3HT fluorescence and charge carrier mobilities.

Mots clés: COIL BLOCK-COPOLYMERS; PHOTOVOLTAIC APPLICATIONS; POLY(3-HEXYLTHIOPHENE); MORPHOLOGY; FULLERENE; POLYMER; FILMS

Domaines: Polymères

Véronique Gernigon, Patrick Leveque, Fanny Richard, Nicolas Leclerc, Cyril Brochon, et al.. Microstructure and Optoelectronic Properties of P3HT-b-P4VP/PCBM Blends: Impact of PCBM on the Copolymer Self-Assembly. Macromolecules, 2013, 46 (22), pp.8824-8831. ⟨10.1021/ma4010692⟩. ⟨hal-00926332⟩