Very High Mobility in Solution-Processed Organic Thin-Film Transistors of Highly Ordered [1]Benzothieno[3,2-b]benzothiophene Derivatives

Field-effect mobility as high as 5 cm(2)/(V S) is achieved in solution-processed organic thin-film transistors with the development of a method for growing highly-oriented crystalline films of [1]benzothieno[3,2-b]benzothiophene derivatives. A droplet of the solution is sustained at an edge of a structure on an inclined substrate, so that the crystalline domain grows in the direction of inclination. The oriented growth realizes excellent molecular ordering that manifests itself in micrometer-scale molecular terraces on the surface as a result of the self-organizing function of the material. The unprecedented performance achieved using an easy fabrication process has increased attractiveness of organic thin-film transistors for industrial applications. (C) 2009 The Japan Society of Applied Physics