Air-stable n-channel organic field-effect transistors based on a sulfur rich π-electron acceptor

Abstract

International audienceThin-film and single-crystal n-channel organic field-effect transistors are built from the sulfur rich π-electron acceptor, (E)-3,3′-diethyl-5,5′-bithiazolidinylidene-2,4,2′,4′-tetrathione (DEBTTT). Different source and drain electrode materials are investigated: gold, the conducting charge transfer salt (tetrathiafulvalene)(tetracyanoquinodimethane), and carbon paste. Regardless of the nature of the electrodes, air-stable n-channel transistors have been obtained. Single crystals exhibit a higher performance than the thin-film transistors with a mobility of up to 0.22 cm2 V−1 s−1. These thin-film and single-crystal devices exhibit excellent long-term stability as demonstrated by the mobility measured during several weeks. The high mobility and air stability are ascribed to the characteristic three-dimensional S–S network coming from the thioketone sulfur atoms

Temperature-dependent characteristics of n-channel transistors based on 5,5′-bithiazolidinylidene-2,4,2′,4′-tetrathiones

“…[1][2][3] These materials are obtained as a side-product of single-component organic metals, 4,5 but seemingly a very stable compound, 6 and show a strong acceptor ability, whose lowest unoccupied molecular orbitals (LUMO) are located around −4.2 eV. 2 We have first found the excellently air-stable n-channel transistor properties mainly in the single-crystal transistors of the ethyl compound (SS-Et), 1 but later found similar performance and air stability in the evaporated films of the n-propyl compound (SS-Pr). 2 The alkyl chain length has been increased up to n-butyl, but the performance decreases, 2 though the 2-phenylethyl compound shows a comparatively high mobility of 0.27 cm 2 V -1 s -1 .…”

Impact of bulky phenylalkyl substituents on the air-stable n-channel transistors of birhodanine analogues

“…Previously, we have reported remarkable transistor characteristics and air stability in n-type organic transistors of sulfurrich acceptors, 3,3 0 -dialkyl-5,5 0 -bithiazolidinylidene-2,2 0 -dione-4,4 0 -dithione (OS-R) and 3,3 0 -dialkyl-5,5 0 -bithiazolidinylidene-2,4,2 0 ,4 0 -tetrathiones (SS-R) (R ¼ alkyl in Scheme 1). 3,4 SS-R compounds show stronger electron acceptor ability than OS-R stemming from the stability of the thiolate units (S À ) because the negative charges are largely located on the inner thiocarbonyl groups. SS-Pr shows the highest mobility of 0.26 cm 2 V À1 s À1 among this series of materials, and achieves remarkable long-term stability even in the thin-lm transistors.…”

A sulfur-rich π-electron acceptor derived from 5,5′-bithiazolidinylidene: charge-transfer complex vs. charge-transfer salt

“…6,7 Within this framework, we recently reported the synthesis of a sulfur-rich electron acceptor, the DEBTTT [(E)-3,3′-diethyl-5,5′-bithiazolidinylidene-2,4,2′,4′-tetrathione], which has proved to be a valuable acceptor in the preparation of CT salt with [Fe(Cp* It is worth mentioning that DEBTTT is also a valuable candidate in the elaboration of air-stable n-channel organic field-effect transistors, since the rare presence of sulfur atoms in such acceptors favor stronger intermolecular interactions for enhanced charge mobilities. 9 Nevertheless, the oxidizing ability of this acceptor is below those traditionally used to oxidize tetrathiafulvalene derivatives. Thus, there is an interest in extending this new family of acceptors, by increasing their electron acceptor ability.…”