Domain Wall-Induced Electronic Reconstruction and Polarization Enhancement in Bilayer 3R-MoS₂

Yee-Heng Teh^1*, Horng Tay Jeng¹

¹物理系, 國立清華大學, 新竹市, Taiwan

* Presenter:Yee-Heng Teh, email:sucittoteh@gapp.nthu.edu.tw

Bilayer 3R-MoS₂ has unique ferroelectric polarization switching mechanism, which in-plane sliding displacement of individual MoS₂ layers would reverse out-of-plane polarization. Domain walls are essential for polarization switching in 3R-MoS₂, their structural and dynamical properties have been extensively studied but the change in electronic and ferroelectric properties upon domain wall formation remains unclear. In this work, we use density functional theory (DFT) to investigate ferroelectric polarization profile of supercells connected with domain walls. We demonstrate that atomic reconstruction within the domain wall region would create in-plane dipole moment at opposite surfaces, thereby enhancing the out-of-plane polarization of neighboring ferroelectric domains. The magnitude of enhancement and polarization profile along the domain wall's normal axis are correlated to the sliding deformation of atoms within the domain walls. Our theoretical study elucidates novel ferroelectric enhancement mechanism arising from ferroelectric domain wall formation.

Keywords: ferroelectric, MoS2, Domain Wall, DFT