The heterointerfaces between ferroelectrics and 2D van der Waals (vdW) materials can be utilized to achieve novel interfacial coupling, nonvolatile field effect control, and nanoscale programmable functionalities. In this talk, I will discuss a range of emergent phenomena in ferroelectric/vdW heterostructures mediated by interfacial charge- and lattice-coupling. Leveraging the interface-epitaxy between ferroelectric copolymer P(VDF-TrFE) and 1T’-ReS₂, we have fabricated large scale P(VDF-TrFE) thin films composed of highly ordered, close-packed, 10 and 35 nm wide crystalline nanowires [1]. Combining the polarization doping with nanoscale domain patterning enables local tuning of the carrier density in the vdW channel, which can lead to programmable Schottky junction states in MoS₂ [2]. This approach has also been exploited to create directional conducting paths in an insulating ReS₂ channel, which reveals that the conductivity ratio between the directions along and perpendicular to the Re-chain can exceed 5.5×10⁴ in monolayer ReS₂ [3]. We also observe an unconventional filtering effect of second harmonic generation signal resulting from the polar alignment between monolayer MoS₂ and the chiral rotation of surface dipoles at the domain walls in ferroelectric oxide Pb(Zr,Ti)O₃ [4]. Our study showcases the rich research opportunities offered by integrating ferroelectrics with 2D materials.

[1]  Li et al., Adv. Mater. 33, 2100214 (2021).

[2]  Xiao et al., Phys. Rev. Lett. 118, 236801 (2017).

[3]  Li et al., Phys. Rev. Lett. 127, 136803 (2021).

[4]  Li et al., Nat. Commun. 11, 1422 (2020).