Electronic and surface properties of pentacene films deposited on SiO_2 prepared by the sol-gel and thermally grown methods

摘要

This study investigates the effect of different types of SiO_2 on the electronic and surface properties of pentacene films. Developing better contacts on dielectrics is one of the main challenges for pentacene-based transistor technology. The water contact angle variation indicates more hydrophobic thermally grown SiO_2 surfaces than sol-gel SiO_2 surfaces, suggesting that the thermally grown SiO_2 dielectric enables a better molecular arrangement as the pentacene layer is deposited. It is found that the carrier mobility in pentacene on thermally grown SiO_2 dielectrics is higher than that in pentacene on sol-gel SiO_2 dielectrics. The Hall-effect analysis by using the polaron theorv revealed that the enhanced carrier mobility is due to the increased soacine between molecules.