via ferroelectric domain controlled nanowire patterning*

The layered van der Waals material ReS₂ exhibits highly anisotropic band structure in the 1T' phase. In this work, we probe the effect of the band anisotropy on the transport properties of single- and few-layer ReS₂ via ferroelectric field effect combined with ferroelectric domain patterning. We fabricated mechanically exfoliated ReS₂ flakes into two-point transistor devices sandwiched between a SiO₂/Si back gate and a ferroelectric polymer PVDF-TrFE thin film top layer. The polarization of PVDF was then controlled at the nanoscale using conductive atomic force microscopy. By uniformly polarizing the ferroelectric top layer into the up (P_up) and down (P_down) directions, we induced up to 10⁵ current switching in bilayer ReS₂ channel at 300 K. We then polarized the entire channel into the insulating state, and created a nanoscale line-domain across the channel, leading to a conductive nanowire. By creating nanowires at different orientations, we mapped out the angular dependence of ReS₂ conductivity, which reveals more than one order of magnitude difference between the directions along and perpendicular to the b-axis. We compared the results with DFT calculated band structure of ReS₂.