Solvent Dependence of Vacuum-Dried C₆₀ Thin-Film Transistors

Abstract

We demonstrated solution-processed C60 thin-film transistors with high electron mobility. C60 solutions in various organic solvents were dried in a vacuum chamber to obtain uniform thin films. While C60 solution dried under atmospheric pressure produced a large number of crystals, vacuum-dried C60 solution provided flat and uniform thin films of sufficiently high quality to fabricate thin-film transistors. In spite of amorphous-like thin-film formation, C60 transistors showed strong solvent dependence. High performance C60 thin-film transistors with field-effect mobility of 0.86 cm2 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 ×106 were obtained from 1,2,4-trichlorobenzene C60 solution.

Polaron Structure and Transport in Fullerene Materials: Insights from First-Principles Calculations

“…Of the various materials that have been explored as possible electron acceptors in FETs, C 60 fullerenes ,,− and C 70 fullerenes and their derivatives have been used in a large number of studies and have shown some of the more promising electron mobilities . C 70 has also been studied extensively as an electron-acceptor in OPVs, − with C 70 -based acceptors offering increased photoabsorption over a large energy range relative to the traditional C 60 -based acceptors .…”

Solution-Processed C60 Single-Crystal Field-Effect Transistors

“…[12][13][14] Solution-processed amorphous or polycrystalline C 60 transistors have been fabricated by spincoating, vacuum-drying, and drop-casting. [15][16][17] Recently, Li and cowokers have demonstrated very high electron mobility using the droplet-pinned crystallization method, which provides very high quality C 60 crystal arrays. 18,19) Although high electron mobilities were obtained from solutionprocessed amorphous and crystalline C 60 thin films, the influence of solvent residues was not discussed adequately.…”