title: Probing the nanoscale phase separation and photophysics properties of low-bandgap polymer:fullerene blend film by near-field spectroscopic mapping.
abstract: The effect of the additive 1,8-octanedithiol (ODT) on the nanometer-scale morphology and local photophysical properties of low-bandgap polymer blends of poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b'] dithiophene)- alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) and [6,6]-phenyl C(61) -butyric acid methyl ester (PCBM) is investigated. Phase separations of the PCPDTBT:PCBM blend film induced by ODT are visualized by the morphological changes from fibril-shaped features to spherical bumps, by the dramatically increased photoluminescence emission from PCPDTBT that was originally largely quenched, and by the fluctuations of spectral features at different locations of the sample surface. The correlations between the morphology and the local photophysical properties of the blend film with/without ODT at both the micrometer and nanometer scales are revealed by confocal and high-resolution near-field spectroscopic mapping techniques.
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.forename: Hamed
authors.initials: H
authors.lastname: Azimi
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Mack
authors.forename: Mauro
authors.initials: M
authors.lastname: Morana
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Egelhaaf
authors.forename: Alfred J
authors.initials: AJ
authors.lastname: Meixner
authors.forename: Dai
authors.initials: D
authors.lastname: Zhang
mesh_terms: D037741:Fullerenes / Q000737:chemistry*; D008027:Light; D018613:Microscopy, Confocal; D053758:Nanoparticles / Q000737:chemistry*; D055095:Optics and Photonics; D044367:Phase Transition / Q000528:radiation effects*; D011108:Polymers / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013830:Thiadiazoles / Q000737:chemistry
chemical_list: C539575:(6,6)-phenyl C61-butyric acid methyl ester; D037741:Fullerenes; D011108:Polymers; D013438:Sulfhydryl Compounds; D013830:Thiadiazoles; C555055:poly(2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta(2,1-b-3,4-b0)dithiophene))-alt-4,7-(2,1,3-benzothiadiazole); C516316:1,8-octanedithiol