Graphene Field-Effect Transistors with Ferroelectric Gating

Abstract

Recent experiments on ferroelectric gating have introduced a novel functionality, i.e., nonvolatility, in graphene field-effect transistors. A comprehensive understanding in the nonlinear, hysteretic ferroelectric gating and an effective way to control it are still absent. In this Letter, we quantitatively characterize the hysteretic ferroelectric gating using the reference of an independent background doping (n(BG)) provided by normal dielectric gating. More importantly, we prove that n(BG) can be used to control the ferroelectric gating by unidirectionally shifting the hysteretic ferroelectric doping in graphene. Utilizing this electrostatic effect, we demonstrate symmetrical bit writing in graphene-ferroelectric field-effect transistors with resistance change over 500% and reproducible no-volatile switching over 10⁵ cycles.

Ferroelectrically driven spatial carrier density modulation in graphene

“…Devices based on this concept have demonstrated non-volatile resistance hysteresis [13][14][15] and transparent conductivity in flexible electronics 16,17 . Initial experimental studies, however, achieved charge density changes in graphene much smaller than anticipated from full compensation of the polarization 18 , since the electrostatic coupling can be limited by extrinsic effects caused by adsorbed molecules 15,19,20 . The atomistic details and interfacial chemistry governing the interaction and the resulting charge density changes in graphene remain elusive.…”

Modulation of mid-IR radiation by a gated graphene on ferroelectric substrate

“…An unusual hysteresis in the resistance has been found to occur in the gate sweeps at high voltages, due to ferroelectric properties of the substrates. However, the epitaxial ferroelectric thin films of Pb(Zr x Ti 1-x )O 3 (PZT) behave as high-κ dielectrics at low voltages (V < V cr ~ 1-2 V), with κ = 73 (x = 0.2 [5]) or even κ = 400 (x = 0.3) [6]. This should allow one to use them in low-voltage mid-IR gated graphene-based modulators.…”

“…Graphene placed on such the substrates has been intensively studied in the recent years (see, e.g., [5][6][7]). An unusual hysteresis in the resistance has been found to occur in the gate sweeps at high voltages, due to ferroelectric properties of the substrates.…”

Ferroelectric domain triggers the charge modulation in semiconductors (invited)

“…Several experimental and theoretical studies consider intriguing physical properties of the heterostructure graphene/physical gap or dielectric layer/ferroelectric substrate [37, 38,39,40,41,42,43]. Interest to the heterostructures is primary related with tempting possibility to add next level of functionality by electric field and temperature control over the spontaneous polarization direction, value and domain structure properties in the vicinity of surface [43].…”