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Connecting soft x-ray anisotropy with local order in conjugated polymers

Published online by Cambridge University Press:  11 September 2019

Joshua H. Litofsky
Affiliation:
Department of Chemical Engineering, The Pennsylvania State University, University Park, PA16802, USA
Enrique D. Gomez*
Affiliation:
Department of Chemical Engineering, The Pennsylvania State University, University Park, PA16802, USA Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA16802, USA Materials Research Institute, The Pennsylvania State University, University Park, PA16802, USA
*
Address all correspondence to Enrique D. Gomez at edg12@psu.edu
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Abstract

Polarized resonant soft x-ray scattering (RSoXS) can leverage contrast between domains in mass, chemical bonds, and chain orientation to characterize polymer thin films. Although mass and chemical contrast can be predicted from the absorption spectra, the origins of orientational contrast are not fully understood. For example, in the case where one domain is crystalline, it is not obvious how the total crystallinity will affect the anisotropy. Using a simple calculation, we predict polarized RSoXS of model structures and compare with experiment. Through experiments and simulations, we demonstrate that scattering anisotropy is not monotonically related to local order but instead peaks when 50% of domains have aligned chains, i.e., when the sample is 50% crystalline.

Type
Research Letters
Copyright
Copyright © The Author(s) 2019

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