New
solution processable 3,5-dithioalkyl dithienothiophene (DSDTT)
based small molecular semiconductors end functionalized with various
(fused) thiophenes including dithienothiophene (DTT), thienothiophene
(TT), and thiophene (T) are synthesized and characterized in organic field effect transistors (OFETs).
The new DSDTT core was synthesized via a one-pot [1 + 1 + 1] methodology.
For comparison, non-thiolated 3,5-dialkyl dithienothiophene (DRDTT)
based molecules are also prepared and characterized. Optical, electrochemical,
and computed electronic structures of these molecules are investigated
and contrasted. Single crystal data support evidence of S(alkyl)···S(thiophene)
intramolecular locks, with a very short intramolecular S–S
distance of 3.17 Å, planarizing the structure as for the equivalent
extended n-thienoacenes. Via a solution-shearing
semiconductor film deposition method, these semiconductors exhibit
a OFET hole mobility up to 2.6 cm2 V–1 s–1, the greatest reported to date for fused/all-thiophene
based small molecular organic semiconductors.
Three new organic semiconductors with alkyl chain-substituted tetrathienoacene (TTAR) as the central core and both ends capped with thiophene (DT-TTAR), thienothiophene (DTT-TTAR) and dithienothiophene (DDTT-TTAR) have been synthesized and characterized for organic field effect transistor (OFET) applications. A hole mobility of 0.81 cm V s was achieved for the DDTT-TTAR film, which represents the highest mobility yet found for a solution-processable p-type TTAR-based small molecular semiconductors.
Four soluble dialkylated tetrathienoacene (TTAR)-based small molecular semiconductors featuring the combination of a TTAR central core, π-conjugated spacers comprising bithiophene (bT) or thiophene (T), and with/without cyanoacrylate (CA) end-capping moieties are synthesized and characterized. The molecule DbT-TTAR exhibits a promising hole mobility up to 0.36 cm 2 V −1 s −1 due to the enhanced crystallinity of the microribbon-like films. Binary blends of the p-type DbT-TTAR and the n-type dicyanomethylene substituted dithienothiophene-quinoid (DTTQ-11) are investigated in terms of film morphology, microstructure, and organic field-effect transistor (OFET) performance. The data indicate that as the DbT-TTAR content in the blend film increases, the charge transport characteristics vary from unipolar (electron-only) to ambipolar and then back to unipolar (hole-only). With a 1:1 weight ratio of DbT-TTAR/DTTQ-11 in the blend, well-defined pathways for both charge carriers are achieved and resulted in ambipolar transport with high hole and electron mobilities of 0.83 and 0.37 cm 2 V −1 s −1 , respectively. This study provides a viable way for tuning microstructure and charge carrier transport in small molecules and their blends to achieve high-performance solution-processable OFETs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.