Anisotropy of carrier mobility is measured for dinaphtho [2,3-b: 2′, 3′ -f] thiopheno [3,2-b] thiophenes single-crystal transistors. We have developed a method of "local gating" to restrict carrier-accumulated channels elongated radially within the herringbone planes of submillimeter crystals so that mixture of conductivity off the intended directions is minimized in the measurement. The highest mobility 4 cm2 /V s is achieved for the a -axis direction due to the highest orbital overlaps, while the lowest mobility measured in the perpendicular direction is still as high as 2.5 cm2 /V s. The moderate anisotropy favors high performance in polycrystalline thin-film transistors of the compound, where charge transport is inevitably mixed for all directions.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)