Interfacial Polarization Enhanced Ultrafast Carrier Dynamics in Ferroelectric CuInP₂S₆

Two-dimensional (2D) ferroelectric materials hold great potential for various electronic applications, including nonvolatile memory, ferroelectric field-effect transistors, and functional sensors. Cooperative phenomena associated with ferroelectricity-modulated carrier dynamics in the 2D context have primarily remained unexplored. To address this gap, we investigate the photoinduced dynamics in CuInP₂S₆ (CIPS) and elucidate the relationship between photoexcited carrier dynamics and interfacial polarizations. The intrinsic polarization substantially prolongs the carrier lifetime assisted by the mitigation of Cu⁺ ions. Additionally, the intralayer carrier recombination within CIPS is significantly accelerated by 2 orders of magnitude upon the formation of heterojunctions with graphene. The carrier dynamics exhibit clear dependence on interfacial polarizations, thereby facilitating the spatial separation of photoinduced carriers. The findings lay the groundwork for future investigation of 2D ferroelectric materials, paving the way for ferroelectric memory and computing technology for industrial applications.