Surfactant Free P3HT/PCBM Nanoparticles for Organic Photovoltaics (OPV)

Initial attempts to prepare conducting polymer nanoparticles with ethanol as a solvent are described. Using poly (3-hexylthiophene) (P3HT)/1-(methoxycarbonylpropyl)-1-phenyl-[6,6]C61 (PCBM) blends we demonstrate surfactant-free synthesis and characterization of polymer nanoparticles in ethanol dispersion. The spectral features of the nanoparticles were investigated by UV-vis spectrophotometry show that P3HT has an absorption maximum at similar to 520 nm, while the absorption peak of PCBM lies at similar to 330 nm. Corresponding fluorescence spectra of the nanoparticles show an emission peak at 630 nm with a shoulder visible at 720 nm. TEM spectra show that the particle size is in the range 35 to 100 nm. Using the ethanol suspension of these particles, we have fabricated and characterized working OPV (organic photovoltaic) devices. This approach is shown to be an effective way to control active layer morphology in OPV devices.