The influence of molecular weight on the microstructure and thin film transistor characteristics of pBTTT polymers

Published

January 1, 2006

Author(s)

Rick Hamilton, Clare Bailey, Warren Duffy, Martin Heeney, Martin Shkunov, David Sparrowe, Steve Tierney, Iain McCulloch, Regis J. Kline, Dean DeLongchamp, Michael L. Chabinyc

Abstract

A common strategy to improve the electrical performance of organic field effect transistors is to optimize the charge carrier mobility of the semiconducting thin film. Polymer semiconductor transport properties have shown a dependence on the chain length, due principally to the strong influence of molecular weight on the thin film microstructure. In this work, we report on a study of the influence of increasing molecular weight of poly(2,5-bis(3-docecylthiophen-2- yl)thieno[3,2-b]thiophenes) (pBTTT-C12) on the polymer bulk thermal properties, thin film microstructure and the electrical performance of thin film field effect transistor devices. Clear differences can be observed within a number average relative molecular mass range of 8000 to 18000. A Liquid crystalline phase was only observed at the highest relative molecular mass, different thin film morphology was observed within the relative molecular mass range, and the field effect mobility was shown to increase with increasing relative molecular mass.

Citation

Proceedings of the SPIE: Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray

Volume

6336

Pub Type

Journals

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Keywords

charge-carrier mobility, molecular weight, polymer transistor

Citation

Hamilton, R. , Bailey, C. , Duffy, W. , Heeney, M. , Shkunov, M. , Sparrowe, D. , Tierney, S. , McCulloch, I. , Kline, R. , DeLongchamp, D. and Chabinyc, M. (2006), The influence of molecular weight on the microstructure and thin film transistor characteristics of pBTTT polymers, Proceedings of the SPIE: Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852700 (Accessed October 12, 2025)