Ferroelectric Single-Crystal Gated Graphene/Hexagonal-BN/Ferroelectric Field-Effect Transistor

Abstract

The effect of a ferroelectric polarization field on the charge transport in a two-dimensional (2D) material was examined using a graphene monolayer on a hexagonal boron nitride (hBN) field-effect transistor (FET) fabricated using a ferroelectric single-crystal substrate, (1-x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] (PMN-PT). In this configuration, the intrinsic properties of graphene were preserved with the use of an hBN flake, and the influence of the polarization field from PMN-PT could be distinguished. During a wide-range gate-voltage (VG) sweep, a sharp inversion of the spontaneous polarization affected the graphene channel conductance asymmetrically as well as an antihysteretic behavior. Additionally, a transition from antihysteresis to normal ferroelectric hysteresis occurred, depending on the V(G) sweep range relative to the ferroelectric coercive field. We developed a model to interpret the complex coupling among antihysteresis, current saturation, and sudden conductance variation in relation with the ferroelectric switching and the polarization-assisted charge trapping, which can be generalized to explain the combination of 2D structured materials with ferroelectrics.

Hysteretic phenomena in GFET: Comprehensive theory and experiment

“…The parameters d = 300 nm, κ=400, P f = 0,1 C/m 2 , max g V ± =4V(a) and =6V (b). Forward sweeping dependences are shown by red curves, the backward one by the black ones.max g V ± The dependences qualitatively similar to those shown in Figures 10 were obtained experimentally for the graphene channel placed on hexagonal BN (hBN) on (1x)[Pb(Mg 1/3 Nb 2/3 )O 3 ]-x[PbTiO 3 ] (PMN-PT) substrate39 . The transition from the direct hysteresis to inverse one was observed there with the increase of the gate voltage switching range, as it is demonstrated inFigure 10.ConclusionUsing a phenomenological approach, we developed a general theory for the analytical description of versatile hysteretic phenomena in GFETs on different substrates.…”

Side‐Gated In2O3 Nanowire Ferroelectric FETs for High‐Performance Nonvolatile Memory Applications

“…Although the gate pulses used in the dynamic characteristic test are much shorter than those used in stability and endurance tests, a dynamic retention ratio of about 10 5 is still observed under V ds of 0.1 V. Here we also studied the current dynamics of devices with the same D and different W (see Figure S6 in the Supporting Information), the result is in good agreement with our discussion about the impact of different gate sizes. All these results demonstrate an excellent nonvolatility memory behavior of our side‐gated FeFETs, by reference to ferroelectric memory with top‐gated or back‐gated structure in previous works 5, 13, 17, 28, 36…”

“…It is as well worth mentioning that the coercive electric field of P(VDF‐TrFE) film appears to be around 50 MV m −1 at the sweep loop frequency of less than 0.1 Hz,30 being larger than the turn‐off electric field of devices with W of 2 μm. We attribute this to our devices that they are operated under the interaction of ferroelectric polarizations and charge traps existed at the interface between the ferroelectric film and the NW;28, 33, 36 therefore, a lower electric field is required. According to the findings of these geometrical effects, we can then optimize the device design and fabrication for different utilizations with varied operating voltages.…”

Nonvolatile MoS2 field effect transistors directly gated by single crystalline epitaxial ferroelectric

“…In fact, these surface states have such a large density that they completely screen out the polarization charge of the ferroelectric (typically > 10 14 / cm 2 ), thereby decoupling the 2D layer from the ferroelectric. For example, a robust trap related hysteresis (often called the 'anti-hysteresis') has been observed in multiple studies [6][7][8][9] . A real ferroelectric induced hysteresis is rare [10][11][12] .…”