Adsorption of Selected Chiral Small Molecules Preserves Stacking‐Dependent Polarization at van der Waals Interfaces

ABSTRACT

Chiral small‐molecule modification provides an interfacial route for functionalizing sliding ferroelectrics. Herein, we systematically investigate four chiral molecules adsorbed on h‐BN, 3R‐MoS ₂ , and γ‐InSe. Across 48 adsorption configurations, the polarization changes range from −27.5% to +13.7%, with a median absolute variation of 10.0%, while 35 configurations show changes within ±15%. The polarization retains its original Up and Down sign in all relaxed configurations examined. The oppositely polarized states remain connected by finite‐energy sliding pathways, although molecular adsorption modifies the barrier heights and endpoint energy asymmetry. Bader charge and charge density difference analyses reveal limited net charge transfer and predominantly localized electronic redistribution near the interface. The relationship between the interfacial charge‐transfer dipole and the Berry‐phase polarization modulation depends on the substrate. These results demonstrate that stacking‐dependent polar states remain present in the investigated chiral‐molecule sliding‐ferroelectric interfaces, providing a microscopic basis for molecular functionalization of sliding ferroelectrics.