Organic semiconductor core–shell nanoparticles designed through successive solvent displacements

Abstract

This study reports for the first time the elaboration of core–shell organic nanoparticles through successive solvent displacements. The concept has been applied to generate donor–acceptor nanoparticles with the commonly used organic semiconductors P3HT and PCBM. The strategy is based on the sequential nanoprecipitation of P3HT and PCBM. Starting from a P3HT:PCBM solution in THF, the first solvent displacement with DMSO triggers the formation of the P3HT core while the second displacement with water generates the PCBM shell. The core–shell morphology is evidenced by both DLS and TEM. Efficient quenching of the P3HT photoluminescence is observed after the second solvent displacement procedure, confirming the formation of a well-defined PCBM shell around the P3HT core. Studying the emission of such core–shell nanoparticles leads to an estimation of the diffusion length of photogenerated excitons in P3HT of around ∼14 nm.