Solvent Dependence of Vacuum-Dried C 60 Thin-Film Transistors

We demonstrated solution-processed C 60 thin-film transistors with high electron mobility. C 60 solutions in various organic solvents were dried in a vacuum chamber to obtain uniform thin films. While C 60 solution dried under atmospheric pressure produced a large number of crystals, vacuum-dried C 60 solution provided flat and uniform thin films of sufficiently high quality to fabricate thin-film transistors. In spite of amorphous-like thin-film formation, C 60 transistors showed strong solvent dependence. High performance C 60 thin-film transistors with field-effect mobility of 0.86 cm 2 V -1 s -1 , threshold voltage of 1.5 V, subthreshold slope of 0.67 V/decade and a current on/off ratio of 3.9 ×10 6 were obtained from 1,2,4-trichlorobenzene C 60 solution.