Nanoparticles (NPs)
of conjugated polymers in intimate contact
with sheets of graphene oxide (GO) constitute a promising class of
water-dispersible nanohybrid materials of increased interest for the
design of sustainable and improved optoelectronic thin-film devices,
revealing properties exclusively pre-established upon their liquid-phase
synthesis. In this context, we report for the first time the preparation
of a P3HTNPs–GO nanohybrid employing a miniemulsion
synthesis approach, whereby GO sheets dispersed in the aqueous phase
serve as a surfactant. We show that this process uniquely favors a
quinoid-like conformation of the P3HT chains of the resulting NPs
well located onto individual GO sheets. The accompanied change in
the electronic behavior of these P3HTNPs, consistently
confirmed by the photoluminescence and Raman response of the hybrid
in the liquid and solid states, respectively, as well as by the properties
of the surface potential of isolated individual P3HTNPs–GO nano-objects, facilitates unprecedented charge transfer
interactions between the two constituents. While the electrochemical
performance of nanohybrid films is featured by fast charge transfer
processes, compared to those taking place in pure P3HTNPsfilms, the loss of electrochromic effects in P3HTNPs–GO
films additionally indicates the unusual suppression of polaronic
charge transport processes typically encountered in P3HT. Thus, the
established interface interactions in the P3HTNPs–GO
hybrid enable a direct and highly efficient charge extraction channel
via GO sheets. These findings are of relevance for the sustainable
design of novel high-performance optoelectronic device structures
based on water-dispersible conjugated polymer nanoparticles.