Alkoxy-substituted polyterthiophene thin film transistors as alcohol sensors

Dipentoxy substituted polyterthiophene thin films are proposed as active layer in organic thin-film-transistor device configuration. Results on their use also as alcohol sensing layers both in a thin-film-transistor (TFT) and in a quartz crystal microbalance (QCM) configuration are presented. Responses to 1-hexanol and ethanol molecules are very fast, extremely reversible and the best extrapolated sensitivities are as good as 0.7 ng/ppm. Device performance and sensing mechanisms are also discussed. (C) 2003 Elsevier B.V All rights reserved

Field-effect sensitivity enhanced bilayer chiral sensor

Organic thin-film transistor sensors have been recently attracting the attention of the plastic electronics community for their potential exploitation in novel sensing platforms. Specificity and sensitivity are however still open issues: in this respect chiral discrimination—being a scientific and technological achievement in itself—is indeed one of the most challenging sensor bench-tests. So far, conducting-polymer solid-state chiral detection has been carried out at part-per-thousand concentration levels. Here, a novel chiral bilayer organic thin-film transistor gas sensor—comprising an outermost layer with built-in enantioselective properties—is demonstrated to show field-effect amplified sensitivity that enables differential detection of optical isomers in the tens-of-parts-permillion concentration range. The ad-hoc-designed organic semiconductor endowed with chiral side groups, the bilayer structure and the thin-film transistor transducer provide a significant step forward in the development of a high-performance and versatile sensing platform compatible with flexible organic electronic technologies

OLIGOTHIOPHENES BEARING POLAR GROUPS FOR ORGANIC THIN FILM TRANSISTORS: SYNTHESIS, CHARACTERIZATION AND PRELIMINARY GAS SENSING RESULTS

The properties of a series of sexithiophenes bearing amide or ester functionalities in the alpha,omega-positions are reported. Isolation of the ester functionalities from the sexithiophene core by an ethylene spacer led to a device with moderate hole mobilities (1.2-10 -2 cm 2 V -1 s -1 ) and on/off ratios (10 3 ). A bottom contact device based on this sexithiophene showed a good response to a 5 ppm NO atmosphere, encouraging future studies on gas sensing OTFT based on these polar-functionalised OTFT