Temperature-Dependent Charge Transport and Polarization Modulation in P(VDF-TrFE)/IZO Ferroelectric Thin-Film Transistors

Abstract Ferroelectric thin-film transistors (FeTFTs) are highly promising for nonvolatile memory and neuromorphic electronics. Investigating temperature-dependent device characteristics can clarify how ferroelectric polarization modulates carrier transport and assess device working reliability under variable thermal conditions. However, most conventional ferroelectrics have a high Curie temperature; high-temperature characterization inevitably changes intrinsic semiconductor performance, which overlaps with polarization modulation, making it difficult to separate the contribution from ferroelectric polarization. Herein, temperature- dependent electrical characteristics are analyzed on flexible IZO-channel FeTFTs with a low-Tc (∼65 °C) 55:45 and a conventional 70:30 P(VDF-TrFE) as ferroelectric gate dielectrics. A polarization-locking method retains preset ON/OFF polarization states via limited gate sweeping during thermal cycles. Experimental results focus on threshold voltage and mobility evolutions with temperature. The results confirm that the temperature-dependent charge transport is synergistically dominated by the temperature-dependent electrical properties in both the semiconductor and ferroelectric layers. The carrier concentration in the IZO layer increases, and the polarization in the ferroelectric layer degrades with temperature, while the gate capacitance exhibits a peak at the Curie point of P(VDF-TrFE). The sharp mobility enhancement near (Tc) is correlated with the ferroelectric phase transition and is consistent with a reduced contribution from polarization-fluctuation-related scattering for both ON- and OFF-state devices. This work deepens the understanding of polarization modulation and thermal stability and guides high-stability ferroelectric device design.