Fachgruppe Nanostrukturierte Materialien    

We have fabricated organic thin-film transistors (OTFTs) using a microcontact printing technique (?CP) that employs thin polydimethylsiloxane stamps on a rigid silicon substrate in order to reduce macroscopic distortions. Systematic variation of the printing pressure, printing time, and concentration of eicosanethiol, the “molecular ink” in the ?CP process, permits the fabrication of devices with smaller channel lengths (Leff) than nominally defined by the stamp. Interdigitated Ti/Au electrode structures with Leff down to 100 nm could be fabricated which, after additional surface treatment and vacuum deposition of ???-dihexylquaterthiophene, yield OTFTs with excellent characteristics.