Limits for the graphene on ferroelectric domain wall p-n-junction rectifier for different regimes of current

Abstract

Here we present the theory of the conductivity of pn junction (pnJ) in graphene channel, placed on ferroelectric substrate, caused by ferroelectric domain wall (FDW) for the case of arbitrary current regime: from ballistic to diffusive one. We calculated the ratio of the pnJ conductions for opposite polarities of voltages, applied to source and drain electrodes of the channel, ratio was studied within Landau-Ginzburg-Devonshire approach. We have demonstrated that rectifying properties of the graphene pnJ become better in the vicinity of Curie temperature. However, for the temperatures higher than Curie temperature the rectifying effect vanishes due to the ferroelectric polarization disappearance.

Influence of Domain Structure in Ferroelectric Substrate on Graphene Conductance (Authors' Review)

“…The graphene separation at FDWs induced by the piezo-effect can change the graphene channel conductance. Below, we briefly review the results of works [14][15][16][17][18] and discuss their correlation with available experimental and other theoretical works.…”

“…The presence of a domain structure in a ferroelectric substrate can lead to the formation of -junctions in graphene [11,12], which are located above the domain walls in the ferroelectric substrate [14][15][16][17][18]. Note that the unique properties of the -junction in graphene have been realized much earlier by the multiple-gate doping of a graphene channel by electrons and/or holes [19][20][21].…”

“…in a singlelayer graphene channel at the 180 ∘ -FDW [14,15]. Specifically, the influence of a ferroelectric domain wall on the ballistic conductance of the graphene channel was studied in our work [14] in the WentzelKramers-Brillouin (WKB) approximation.…”

“…However, the performance of the majority of realistic graphene devices depends on the electron mean free path ∼ 50÷250 nm, so that they operate in the diffusion regime [15]. Since the electron mean free path in the graphene channel is usually much longer than the a typical thickness of the uncharged domain wall in a proper ferroelectric (about 1-10 nm) [36], one can divide a graphene channel of the length between the source and the drain into three sections: a section with the length containing thejunction and two sections located on the both sides from the junction with the total length − (see Fig.…”

“…(2.2) and work [15]]. The permittivity f 33 of ferroelectric in the direction normal to the graphene plane can be rather high: about 500 for piezoceramics (PZT) or even higher (about 5000) for relaxor ferroelectrics.…”