Shape engineering to promote head-tail interactions of electro-optic chromophores

Cheng Zhang, Lianjie Zhang, Stephanie J. Benight, Benjamin C. Olbricht, Lewis E. Johnson, Bruce H. Robinson, Robert A. Norwood, Larry R. Dalton

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


Alignment of dipolar chromophores lies at the heart of organic electro-optic materials research. Among all the factors (e.g., external electric field, temperature, conductivity, etc.) affecting alignment efficiency or order parameter, interchromophore electrostatic interaction has been the focus of attention in the last decade. The strength of dipole interaction is highly dependent not only on dipole moment but also on chromophore shape and chromophore number density. Antiparallel interaction is dominant in the solid state of conventional EO chromophores (long and flat) and prevents electro-optic coefficient (r33) from scaling with chromophore concentration. Despite the great amount of research along various approaches to enhancing alignment, order parameters of organic EO materials are still low (0.13- 0.2 v.s. 1 for a perfect alignment). Antiparallel interaction can be selectively attenuated by attaching bulky groups to the middle part of chromophore. However, it is synthetically challenging to provide sufficient steric protection without causing severe reduction of chromophore concentration. In this paper, we will present the first realization of atomeconomic steric protection of chromophore against H-aggregation in all directions and show evidences for the dominance of head-tail interaction over antiparallel interaction of a highly dipolar chromophore. With the novel shape, the EO coefficients of guest-host films of the chromophore do not show attenuation with increasing concentration up to 100 wt%. The dominance of head-tail interaction also enabled fabrication of optical quality thick films from the neat chromophore and allows poling induced alignment to retain at temperatures above the poling temperature - a phenomenon never observed for other chromophores.

Original languageEnglish (US)
Title of host publicationOptical Processes in Organic Materials and Nanostructures II
StatePublished - 2013
EventOptical Processes in Organic Materials and Nanostructures II - San Diego, CA, United States
Duration: Aug 25 2013Aug 28 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherOptical Processes in Organic Materials and Nanostructures II
Country/TerritoryUnited States
CitySan Diego, CA


  • Dipole alignment
  • Electro-optic chromophore
  • Electro-optic coefficient
  • Head-tail
  • Self-assembly

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Shape engineering to promote head-tail interactions of electro-optic chromophores'. Together they form a unique fingerprint.

Cite this