High performance organic field-effect transistors with fluoropolymer gate dielectric

Electrical stability is essential for a successful commercialization of organic semiconductor devices. We report on organic field-effect transistors with unprecedented electrical stability. The single crystal and thin-film transistors employ a fluorocarbon polymer as gate dielectric (Cytop TM ) and pentacene or rubrene as the organic semiconductor. Cytop TM (Cyclic Transparent Optical Polymer) is easy to be used and can be deposited in air from solution. It is highly hydrophobic and has a very low permittivity of ∈ i = 2.1 - 2.2. Moreover, the material is a good electrical insulator with a very high dielectric breakdown field. Its passive surface leads to extremely stable field-effect transistors with a high field-effect mobility, an outstanding subthreshold swing as low as 0.75 nFV/(decade cm 2 ) and a near zero onset voltage. Of particular significance is the resistance of the devices against long-term gate bias stress. Oligomeric organic semiconductors can have a very high electrical stability when combined with a suitable gate dielectric. Cytop TM is an ideal gate dielectric for organic electronics and it seems very likely that the material leads to outstanding transistors in combination with many small molecule organic semiconductors.