Abstract
Here we report a dielectric approach to verify the channel dependence of the threshold voltage in organic field-effect transistors (OFETs). This approach is based on dielectrics physics, and it shows that the potential drop on the injection electrode reduces the capability of applied voltage to accumulate charges that contribute to carrier transport along the channel, which is interpreted as a shift of the threshold voltage. That is, contact resistance is an origin of the channel-length-dependent threshold voltage.