Molecular Ordering of High‐Performance Soluble Molecular Semiconductors and Re‐evaluation of Their Field‐Effect Transistor Characteristics

We introduce the development of conductive organic molecular assemblies including organic metals, superconductors, single component conductors, conductive films, and conductive liquids, particularl...

Development of Conductive Organic Molecular Assemblies: Organic Metals, Superconductors, and Exotic Functional Materials

Organic thin-fi lm transistors (OTFTs) have attracted great interest for their potential use in several electronic applications, including active-matrix displays, electronic paper, and chemical sensors. [ 1 ] Among the many semiconducting materials evaluated in the TFT confi guration, pentacene is the best as it shows the highest fi eld-effect mobility ( > 3.0 cm 2 V − 1 s − 1 ). [ 2 , 3 ] On the other hand, new organic semiconductors are being actively investigated to further improve the performance of OTFTs. In fact, superior unconventional organic semiconductors used to produce high-performance OTFTs have been recently reported, including picene (3.2 cm 2 V − 1 s − 1 ), [ 4 ] trans -1,2-dithieno[2,3b ′ :3,2d ′ ]thiophene ethene (DTTE, 2.0 cm 2 V − 1 s − 1 ), [ 5 ] dithieno[2,3d ;2 ′ ,3 ′ d ′ ]benzo[1,2b ;4,5b ′ ]dithiophene (DTBDT, 1.7 cm 2 V − 1

Alkylated dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophenes (Cn-DNTTs): Organic semiconductors for high-performance thin-film transistors

Single-crystal field effect transistors of the organic semiconductor dithiophene-tetrathiafulvalene (DT-TTF) were prepared by drop casting. Long, thin crystals connected two microfabricated gold electrodes, and a silicon substrate was used as a back gate. The highest hole mobility observed was 1.4 cm2/Vs, which is the highest reported for an organic semiconductor not based on pentacene. A high ON/OFF ratio of at least 7 x 105 was obtained for this device.

/pdf/high-mobility-of-dithiophene-tetrathiafulvalene-single-1bnbbznvbx.pdf

High mobility of dithiophene-tetrathiafulvalene single-crystal organic field effect transistors.

The Reactivity of Tetrathia- and Tetraselenafulvalenes*

We have found a class of highly conductive single-component organic semiconductors; the tetrakis(alkylthio)tetrathiaful-valenes, and have given these systems the descriptive title of 'molecular fastener'1,2. In a programme to synthesize single-component molecular assemblies with high conductivity, we then discovered a new organic semiconductor, tetrakis(alkyltel-luro)tetrathiafulvalene, of electrical resistivity 8.1 x 104 Ωcm, having high charge mobility, 20–30 cm2 V–1 s–1. We explain this unusually low resistivity in terms of molecular packing and stacking manner within the crystal. The central skeleton of this compound, tetratelluro-tetrathiafulvalene moiety (C6Te4S4), is almost planar and is regularly stacked in the form of column. Along the stacking axis, tellurium atoms in neighbouring columns come close each other and form zigzag chains. The distance between those two Te atoms is 3.644(2) A, which is significantly shorter than van der Waals distance (4.12 A). It is expected that zigzag chalcogen chains formed from quasi-covalent bonds.

T. Enoki

Papers

Tetrakis(methyltelluro)tetrathiafulvalene (TTeC1TTF), a high-mobility organic semiconductor