Band-like transport in solution-crystallized organic transistors

Patternable solution-crystallized organic transistors are developed with high carrier mobility that exceeds 10 cm2/V. We have investigated techniques of crystallization during the fabrication of organic semiconductor thin films from solution. Regulating direction of the crystal growth in the process, we successfully formed crystalline films with the mobility as high as 10-12 cm2/V from newly developed air-stable organic semiconductor compounds of 2,7-dialkyl[1]benzothieno[3,2-b]benzothiophene (Cn-BTBT) and 2,9-dialkyl-dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (Cn-DNTT). Furthermore, comprehensive measurements of Hall-effect and temperature dependent mobility for solution-crystallized single-crystal transistors tell us that their fundamental charge-transport mechanism is band transport.