Non Volatile MoS$_{2}$ Field Effect Transistors Directly Gated By Single Crystalline Epitaxial Ferroelectric

TL;DR

This paper demonstrates non-volatile MoS2 transistors directly gated by epitaxial ferroelectric PZT, showing high performance and controllable hysteresis, enabling integration of 2D electronics with functional oxides.

Contribution

It introduces a method to fabricate high-performance, non-volatile MoS2 transistors directly on epitaxial ferroelectric PZT, enabling direct control of channel charge via ferroelectric polarization.

Findings

Transistors exhibit ON current of 19 μA/μm and high on-off ratio of 10^7.

Ferroelectric polarization directly controls the channel charge with observable hysteresis.

Switching of ferroelectric polarization correlates with changes in channel current.

Abstract

We demonstrate non-volatile, n-type, back-gated, MoS$_{2}$ transistors, placed directly on an epitaxial grown, single crystalline, PbZr$_{0.2}$Ti$_{0.8}$O$_{3}$ (PZT) ferroelectric. The transistors show decent ON current (19 ${\mu}A/{\mu}$m), high on-off ratio (10$^{7}$), and a subthreshold swing of (SS ~ 92 mV/dec) with a 100 nm thick PZT layer as the back gate oxide. Importantly, the ferroelectric polarization can directly control the channel charge, showing a clear anti-clockwise hysteresis. We have selfconsistently confirmed the switching of the ferroelectric and corresponding change in channel current from a direct time-dependent measurement. Our results demonstrate that it is possible to obtain transistor operation directly on polar surfaces and therefore it should be possible to integrate 2D electronics with single crystalline functional oxides.