TY - JOUR
T1 - Perfluoroalkyl-functionalized thiazole-thiophene oligomers as N-channel semiconductors in organic field-effect and light-emitting transistors
AU - Usta, Hakan
AU - Sheets, William Christopher
AU - Denti, Mitchell
AU - Generali, Gianluca
AU - Capelli, Raffaella
AU - Lu, Shaofeng
AU - Yu, Xinge
AU - Muccini, Michele
AU - Facchetti, Antonio
N1 - Publisher Copyright:
© 2014 American Chemical Society.
PY - 2014/11/25
Y1 - 2014/11/25
N2 - Despite their favorable electronic and structural properties, the synthetic development and incorporation of thiazole-based building blocks into n-type semiconductors has lagged behind that of other π-deficient building blocks. Since thiazole insertion into π-conjugated systems is synthetically more demanding, continuous research efforts are essential to underscore their properties in electron-transporting devices. Here, we report the design, synthesis, and characterization of a new series of thiazole-thiophene tetra- (1 and 2) and hexa-heteroaryl (3 and 4) co-oligomers, varied by core extension and regiochemistry, which are end-functionalized with electron-withdrawing perfluorohexyl substituents. These new semiconductors are found to exhibit excellent n-channel OFET transport with electron mobilities (μe) as high as 1.30 cm2/(V·s) (Ion/Ioff > 106) for films of 2 deposited at room temperature. In contrary to previous studies, we show here that 2,2′-bithiazole can be a very practical building block for high-performance n-channel semiconductors. Additionally, upon 2,2′- and 5,5′-bithiazole insertion into a sexithiophene backbone of well-known DFH-6T, significant charge transport improvements (from 0.001-0.021 cm2/(V·s) to 0.20-0.70 cm2/(V·s)) were observed for 3 and 4. Analysis of the thin-film morphological and microstructural characteristics, in combination with the physicochemical properties, explains the observed high mobilities for the present semiconductors. Finally, we demonstrate for the first time implementation of a thiazole semiconductor (2) into a trilayer light-emitting transistor (OLET) enabling green light emission. Our results show that thiazole is a promising building block for efficient electron transport in π-conjugated semiconductor thin-films, and it should be studied more in future optoelectronic applications.
AB - Despite their favorable electronic and structural properties, the synthetic development and incorporation of thiazole-based building blocks into n-type semiconductors has lagged behind that of other π-deficient building blocks. Since thiazole insertion into π-conjugated systems is synthetically more demanding, continuous research efforts are essential to underscore their properties in electron-transporting devices. Here, we report the design, synthesis, and characterization of a new series of thiazole-thiophene tetra- (1 and 2) and hexa-heteroaryl (3 and 4) co-oligomers, varied by core extension and regiochemistry, which are end-functionalized with electron-withdrawing perfluorohexyl substituents. These new semiconductors are found to exhibit excellent n-channel OFET transport with electron mobilities (μe) as high as 1.30 cm2/(V·s) (Ion/Ioff > 106) for films of 2 deposited at room temperature. In contrary to previous studies, we show here that 2,2′-bithiazole can be a very practical building block for high-performance n-channel semiconductors. Additionally, upon 2,2′- and 5,5′-bithiazole insertion into a sexithiophene backbone of well-known DFH-6T, significant charge transport improvements (from 0.001-0.021 cm2/(V·s) to 0.20-0.70 cm2/(V·s)) were observed for 3 and 4. Analysis of the thin-film morphological and microstructural characteristics, in combination with the physicochemical properties, explains the observed high mobilities for the present semiconductors. Finally, we demonstrate for the first time implementation of a thiazole semiconductor (2) into a trilayer light-emitting transistor (OLET) enabling green light emission. Our results show that thiazole is a promising building block for efficient electron transport in π-conjugated semiconductor thin-films, and it should be studied more in future optoelectronic applications.
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U2 - 10.1021/cm503203w
DO - 10.1021/cm503203w
M3 - Article
AN - SCOPUS:84912523575
SN - 0897-4756
VL - 26
SP - 6542
EP - 6556
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 22
ER -