C60thin-film transistors with high field-effect mobility, fabricated by molecular beam deposition

Abstract
We report performance of C60 thin-film field-effect transistors and characterizations of C60 thin-films on SiO2 substrates fabricated by molecular beam deposition. Devices, fabricated and characterized under high vacuum without exposing to air, routinely showed current on/off ratios >108 and field-effect mobility in the range of 0.5–0.3 cm2/V s. The obtained mobility is comparable to the highest value among n-type organic thin-film transistors and close to that derived from the photocurrent measurements on C60 thin-films. The grain size of C60 thin-film, condensed in an fcc solid, increases with the substrate temperature, while the mobility did not exhibit a clear relation with substrate temperature.