Bottom-contact organic field-effect transistors based on single-crystalline domains of 6,13-bis(triisopropylsilylethynyl) pentacene prepared by electrostatic spray deposition

Large crystalline domains (a few hundred micrometers in size) of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) were prepared by electrostatic spray deposition (ESD) and used as the active layers of bottom-contact organic field-effect transistors. The TIPS pentacene active layers were directly patterned via a shadow mask in the ESD process. The device, which had a 5-mu m-long channel composed of a single-crystalline domain, exhibited a high field-effect mobility of more than 0.1 cm(2)/V s but resulted in a high threshold voltage of -17 V. The threshold voltage could be lowered to -6.4 V by reducing the thickness of the BC electrodes from 30 to 10 nm; this threshold voltage lowering was probably due to an improvement in the charge injection from the source electrode to the active layer. (C) 2013 Elsevier B.V. All rights reserved.