Anisotropic mobility of small molecule-polymer blend channel in organic transistor: Characterization of channel materials and orientation

We report on the anisotropic properties of solution-processed thin-film transistors (TFTs) fabricated by the vertical flowing of the viscous 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) and isotactic (i-) poly-(methyl methacrylate) (PMMA) blend. During film formation processes, lateral crystalline growth of TIPS-pentacene and TIPS-pentacene/i-PMMA phase-separation were observed. Such anisotropic crystallization of TIPS-pentacene channel caused anisotropic mobility with respect to the channel orientation, so that it could be used for composing of a logic inverter where two TFTs with different channel orientations were serially connected.