We developed an on-chip microfabricated architecture for high-accuracy gate voltage modulated Seebeck coefficient measurements on an organic field-effect transistor (FET). The microfabricated device comprises integrated heaters and temperature sensors that enable simultaneous Seebeck and FET measurements on devices with practical channel lengths on the order of 50 μm. We exemplify the capabilities of this architecture by investigating the transition from conduction in the semiconductor bulk to conduction in the accumulation layer of a conjugated polymer FET.
