n-Type thiophene semiconductors
The new fluorocarbon-functionalized and/or heterocycle-modified polythiophenes, in particular, α,ω-diperfluorohexylsexithiophene DFH-6T can be straightforwardly prepared in high yield and purity. Introduction of such modifications to a thiophene core affords enhanced thermal stability and volatility, and increased electron affinity versus the unmodified compositions of the prior art. Evaporated films behave as n-type semiconductors, and can be used to fabricate thin film transistors with FET mobilities ˜0.01 cm 2 /Vs—some of the highest reported to date for n-type organic semiconductors.
1 . An n-type polythiophene composition having the structural formula
wherein R 1 , R 2 and R 3 are selected from the substituent group consisting of fluoroalkyl moieties, C n H 2n+1 and where n is about 1-12, H, F and (CH 2 ) a X and where a is about 1-12 and X is selected from the group consisting of amino, hydroxy and carboxylic acid functionalities; and x, y and z are integers selected from the group of integers consisting of 0 and integers greater than 0.
2 . The n-type polythiophene composition of claim 1 wherein said fluoroalkyl moiety is selected from the group consisting of linear fluoroalkyl substituents, branched fluoroalkyl substituents and cyclic fluoroalkyl substituents.
3 . The n-type polythiophene composition of claim 2 wherein said fluoroalkyl moiety has a compositional formula C n F 2n+1 , where n is about 1-8.
4 . The n-type polythiophene composition of claim 1 wherein x is about 0-4; y is about 0-8, and z is about 0-12.
5 . The n-type polythiophene composition of claim 4 wherein said fluoroalkyl moiety has the compositional formula C n F 2n+1 , where n is about 1-8.