Anisotropic charge transport and contact resistance of 6,13-bis(triisopropylsilylethynyl) pentacene field-effect transistors fabricated by a modified flow-coating method

Abstract

Using a modified flow-coating method, bottom-gate/bottom-contact type organic field-effect transistors (OFETs) with a highly oriented active layer of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) were fabricated. The flow-coated TIPS-pentacene films were fairly uniform and consisted of arrays of needle-shaped crystals along the flow-coating direction. The uniformity allowed us to determine the contact resistance by a transfer line method. The usefulness of the modified flow-coating method for fabricating high performance OFETs has been demonstrated, and we found that not only the field-effect mobility but also the contact resistance significantly depends on the channel current direction with respect to the flow-coating direction.