Fachgruppe Nanostrukturierte Materialien    

We report on mobilities up to 3.6 cm2/V s in organic field-effect transistors (OFETs) with solution-processed dithiophene- and dibenzo-tetrathiafulvalene (DT- and DB-TTF) single crystals as active materials. In the devices, the channel length varies from 100 ?m down to sub 100 nm, and the SiO2 thickness is either 100 nm, 50 nm, or 20 nm. The devices exhibit excellent operation characteristics with an on/off-ratio exceeding 106. Temperature dependent measurements between 50 and 400 K reveal a thermally activated transport with increased activation above 200 K. The mobility exhibits exponential activation with two distinct exponents.