Dielectric Selection for Solution-Processed High-Mobility TIPS-Pentacene Microwire Field-Effect Transistors

The dielectric effect on the mobility of the solution-processed organic field-effect transistors (OFETs) remains unknown. A major challenge is that most of the solution-processed OFETs are obtained on hydrophilic dielectrics, while most of the commonly used dielectrics for high-mobility OFETs are hydrophobic. In this work, by selecting a preferred solvent to ensure the good wettability of 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) solution on both hydrophobic and hydrophilic dielectrics, the highly ordered TIPS-pentacene single-crystal microwire arrays are in situ grown on the hydrophobic and hydrophilic dielectrics via a solution-processed method, and the dielectric effect on the mobility of the solution-processed TIPS-pentacene OFETs is investigated. The highest mobility on the divinyltetramethyldisiloxane-bis(benzocyclobutene) (BCB)/SiO2 dielectric is ascribed to the matching of both the polar and dispersive components of surface energy between dielectric and semiconductor. This work powerfully confirms the direct effect of the dielectric properties on mobility, and provides a new method to select the optimized dielectric for solution-processed high-mobility OFETs.