Built-in water resistance in organic transistors modified with self-assembled monolayers
We systematically investigated the effects of a self-assembled monolayer (SAM), prepared on the gate dielectric, on the performances of bottom-gate organic field-effect transistor (OFET) devices under various humid environments. OFETs prepared with gate dielectrics modified by depositing a hydrophilic SAM display large variations in their carrier mobilities and on/off ratios when operated under dry or humid conditions. By contrast, the performances of OFETs with a hydrophobic SAM remain relatively constant, regardless of the humidity level. The stability conveyed by the hydrophobic SAM in the presence of humidity is closely related to the water resistance of the SAM, which is based on the hydrophilic and hydrophobic characteristics of the modified gate dielectric.