Jump to main content
Jump to site search


The Correspondence between Conformational and Chromophoric Properties of Amorphous Conjugated Polymer in Mesoscale Condensed System

Abstract

For π-conjugated polymers, the notion of spectroscopic units or “chromophores” provides illuminating insights into the experimentally observed absorption/emission spectra and the mechanisms of energy/charge transfer. To date, however, no statistical analysis has revealed a direct correspondence between chromophoric and conformational properties—the latter being fundamental to polymer semiconductors. Herein, we propose a “persistence length” calculation to re-evaluate chain conformation over a full conjugation length. The mesoscale condensed systems of MEH-PPV and MEH-PPV/C60 hybrid (system size ~10×10×10 nm3) are utilized as two prototypical model systems, along with a full range of segmental lengths (2~20-mer) and five lowest singlet excited states to hint at the generality of the features presented. We demonstrate, for the first time, that two properly redefined conformational factors that characterize chain folding and planarity, respectively, capture excellently the population distribution of chromophore in both systems investigated. In contrast, the conventional strategy of utilizing two adjacent monomer units to characterize (local) chain conformation results in only inconspicuous correlation between the two, as previously reported. It is further shown that chain folding—but not chain planarity—is more relevant in capturing the associated oscillator strength for the first excited state, where the transient dipole moments are known to align with the chain conformation, although the corresponding excitation energy and exciton size seem relatively unaffected. The observed effects of C60 on the MEH-PPV adsorption spectra also agree with recent experimental trends. Overall, the present findings are expected to aid future multiscale computer simulations and spectroscopy-data interpretations for polymer semiconductors and their hybrid systems.

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 May 2017, accepted on 13 Jul 2017 and first published on 13 Jul 2017


Article type: Paper
DOI: 10.1039/C7CP03415F
Citation: Phys. Chem. Chem. Phys., 2017, Accepted Manuscript
  •   Request permissions

    The Correspondence between Conformational and Chromophoric Properties of Amorphous Conjugated Polymer in Mesoscale Condensed System

    C. I. Wang, C. H. Hsu and C. Hua, Phys. Chem. Chem. Phys., 2017, Accepted Manuscript , DOI: 10.1039/C7CP03415F

Search articles by author

Spotlight

Advertisements