Strategies for Fast-Switching in All-Polymer Field Effect Transistors

Abstract

Low-cost printable field effect transistors (FETs) are typically associated with slow switching characteristics. Dynamic response of polymer field effect transistors (PFETs) is a manifestation of time scales involved in processes such as dielectric polarization, structural relaxation, and transport via disordered-interfacial states. A range of dielectrics and semiconductors are studied to arrive at a parameter which serves as a figure of merit and quantifies the different processes contributing to the switching response. A cross-over from transport limiting factors to dielectric limiting factors in the dynamics of PFETs is observed. The dielectric limited regime in the PFET dynamics is tapped in to explore high speed processes, and an enhancement of switching speed by three orders of magnitude (from 300 s to 400 ns) is observed at channel lengths which can be accessed by low cost printing methods. The device structure utilizes polymer-ferroelectrics (FE) as the dielectric layer and involves a fabrication-procedure which assists in circumventing the slow dynamics within the bulk of FE. This method of enhancing the dynamic response of PFETs is universally applicable to all classes of disordered-FE.