Charge carrier mobility study of a mesogenic thienothiophene derivative in bulk and thin films
- 주제(키워드) Thienothiophene , Ordered mesophase , Charge transport properties , Hole mobility , Time-of-flight , Organic field-effect transistor
- 등재 SCIE, SCOPUS
- 발행기관 ELSEVIER SCIENCE BV
- 발행년도 2014
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000091214
- 본문언어 영어
- Published As http://dx.doi.org/10.1016/j.orgel.2014.01.017
초록/요약
A novel mesogenic 2,5-bis-(5-octylthiophene)-thieno[3,2b]thiophene (TT) derivative has been synthesized. The fused-ring thiophene, end-capped with two octylthiophenes, exhibits ordered lamellar mesophases which were characterized by polarizing optical microscopy, differential scanning calorimetry and small-angle X-ray diffraction at various temperatures. The charge transport properties were investigated by time-of-flight technique as a function of temperature. On cooling from isotropic phase, a maximum hole mobility value of 0.07 cm(2) V (1) s (1) was measured in the highly ordered mesophase of the bulk films. Field-effect transistor experiments on both solution and vacuum deposited thin films have also been performed. The solution-processed films exhibit charge carrier mobilities several orders of magnitude lower than values extracted from bulk time-of-flight curves and from vacuum deposited thin film transistors. This work provides evidence that the melt-processing route is an efficient alternative to commonly used solution-processing for fabrication of charge transporting layers from liquid crystalline semiconductors, with performances comparable to evaporation techniques. (C) 2014 Elsevier B.V. All rights reserved.
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