Ferroelectric Polarization‐Mediated Modulation of Optical Properties in 2D van der Waals Architectures

The integration of 2D ferroelectric materials with 2D photoelectric materials presents a promising avenue for addressing issues related to controlled doping and device integration in layered semiconductors. The reversible and non‐volatile residual polarization inherent to ferroelectrics can provide stable n‐ or p‐type doping for 2D semiconductors. Despite advances in doping strategies for 2D materials, existing techniques, and post‐doping characterization methodologies exhibit limitations, including the challenge of achieving high‐resolution graphical depictions of doped structures. Here, a WS2/CuInP2S6 heterostructure is demonstarted whereby the residual polarization of ferroelectric CuInP2S6 regions with anti‐parallel directions supplies screening charges of opposite signs to WS2 monolayers. This notably alters the ratio of neutral excitons and negatively charged trions within the recombination luminescence of the direct‐gap semiconductor, thereby offering a viable approach for controllable, non‐volatile modulation in 2D systems. Beyond proposing a feasible strategy for patterned doping and effective regulation in 2D semiconductors through interface engineering, this work enhances the understanding of the interplay between ferroelectrics and semiconductors. A WS2/CuInP2S6 heterostructure is fabricated in such a way that screening charges of opposite signs are supplied to WS2 monolayers by the residual polarization of ferroelectric CuInP2S6 regions with antiparallel orientations. This significantly modifies the proportion of negatively charged trions to neutral excitons in the direct‐gap semiconductor's recombination luminescence, providing a feasible method for non‐volatile, controlled modulation in 2D systems.