Environmentally stable organic thin-films transistors: Terminal styryl vs central divinyl benzene building blocks for p-type oligothiophene semiconductors

摘要

A series of linear oligomers combining thiophene, phenyl and vinyl units were designed and synthesized to investigate the influence of the number and sequence of the pi-conjugating groups on the stability and performance of organic thin-film transistors. The optical and electrochemical properties of oligomers in solution were investigated by UV-vis absorption and photoluminescence spectroscopies, and cyclic voltammetry. High vacuum evaporated thin films were investigated by optical absorption, X-ray diffraction and AFM, and implemented as p-type semiconducting layers into organic thin-film transistors (OTFTs). Furthermore, shelf-live tests (under ambient conditions) of the OTFTs based on the distyryl-substituted oligomer, DS-2T, show that the mobility was almost unchanged for 100 days, indicating a high environmental stability and the great importance of end-substitution to provide stability against air-oxidation. (c) 2006 Elsevier B.V. All rights reserved.