Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Classification of Semiconducting Polymeric Mesophases to Optimize Device Post-Processing

Published

Author(s)

Chad R. Snyder, Regis J. Kline, Dean M. DeLongchamp, Ryan C. Nieuwendaal, Lee J. Richter, Martin Heeney, Iain McCulloch

Abstract

Semiconducting polymers form a variety of phases and mesophases that respond differently to post-deposition solvent or thermal treatments. Here it is shown that classification of these materials into their appropriate mesophases can be a useful tool to optimize their post-deposition treatments. Calorimetry is used to quantify differences between materials having similar molecular structures, using a well-established framework based on the kinetics and thermodynamics of phase changes. By way of example, this classification scheme is used to identify differences in three polymers, poly(3-hexylthiophene-2,5-diyl) and two isomeric bithiophene-thiophene copolymers. It is demonstrated that poly(3-hexylthiophene) is a “normal” polymer crystal, and that the two bithiophene copolymers have liquid crystalline phases. The diverse phase structure is notable in light of the molecular similarity of the three polymers, and it has an impact on optimum post-processing conditions for maximum field effect charge carrier mobility in thin film transistor devices. Strong superheating effects are demonstrated for the two bithiophene-thiophene copolymers and the impact on annealing is demonstrated using grazing incidence X-ray diffraction.
Citation
Journal of Polymer Science Part B-Polymer Physics
Volume
53

Keywords

flexible electronics, organic thin film transistors, photovoltaics, mesophases, liquid crystals, polymers

Citation

Snyder, C. , Kline, R. , DeLongchamp, D. , Nieuwendaal, R. , Richter, L. , Heeney, M. and McCulloch, I. (2015), Classification of Semiconducting Polymeric Mesophases to Optimize Device Post-Processing, Journal of Polymer Science Part B-Polymer Physics, [online], https://doi.org/10.1002/polb.23801 (Accessed November 14, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created August 17, 2015, Updated November 10, 2018