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Spectroscopic studies of dopant-induced conformational changes in poly(3-hexylthiophene) thin films

Published online by Cambridge University Press:  07 September 2017

Annabel R. Chew  and
Alberto Salleo
Annabel R. Chew
Affiliation:
Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
Alberto Salleo*
Affiliation:
Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
*
Address all correspondence to Alberto Salleo at asalleo@stanford.edu
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Abstract

The effect of p-type doping at ultra-low concentrations (~10−4–10−5 monomer mol fraction) of the polymer poly(3-hexylthiophene) (P3HT) is studied using charge modulation (CM) spectroscopy. Quantitative analysis of CM spectra of doped P3HT show that dopants induce measurable changes in the P3HT local chain conformation. We find that the dopants reside in both the aggregate and amorphous regions of the polymer, not just in the amorphous regions, as previously assumed. With increased doping, the P3HT intrachain disorder grows, causing the P3HT chains to become more oligomer-like, which we postulate leads to the drop in mobility commonly observed in literature.

Type
Research Letters
Information
MRS Communications , Volume 7 , Issue 3 , September 2017 , pp. 728 - 734
Copyright
Copyright © Materials Research Society 2017 

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