The ambipolar evolution of a high-performance WSe transistor assisted by a ferroelectric polymer.

In recent years, the electrical characteristics of WSe field-effect transistors (FETs) have been widely investigated with various dielectrics. Among them, being able to perfectly tune the polarity of WSe is meaningful and promising work. In this work, we systematically study the electrical properties of bilayer WSe FETs modulated by ferroelectric polymer poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)). Compared to traditional gate dielectric SiO, the P(VDF-TrFE) can not only tune both electron and hole concentrations to the same high level, but also improve the hole mobility of bilayer WSe to 265.96 cm V s under SiO gating. Its drain current on/off ratio is also improved to 2 × 10 for p-type and 4 × 10 for n-type driven by P(VDF-TrFE). More importantly, the ambipolar behaviors of bilayer WSe are effectively achieved and maintained because of the remnant polarization field of P(VDF-TrFE). This work indicates that WSe FETs with P(VDF-TrFE) gating have huge potential for complementary logic transistor applications, and paves an effective way to achieve in-plane p-n junctions.