Emergence of Polarization Wake-Up from an Electric-Field-Induced Order–Disorder Transition in Ferroelectric CuInP ₂ S ₆

Ferroelectrics show great potential in information storage and neuromorphic computing due to unique spontaneous polarization. Two-dimensional layered ferroelectric CuInP2S6 has garnered significant research interest, benefiting from the coupling between ion migration and ferroelectricity. However, unclear mechanisms governing electric-field-induced polarization enhancement in CuInP2S6 hinder its performance optimization and practical application. Herein, we investigate the polarization wake-up effect in CuInP2S6 parallel-plate capacitors by regulating pre-polarization time and temperature combined with first-principles calculations. A critical pre-polarization duration is identified, beyond which polarization is significantly enhanced alongside a disorder-to-order polarization transition, rooted in the matching between Cu+ migration time and electric field pulse width. Moreover, elevated temperature synergistically enhances polarization with the electric field, differing from conventional thermal depolarization. Spatially resolved SHG mapping confirms the intrinsic enhancement. This work clarifies ion migration dynamics in 2D CuInP2S6 and proposes a temperature–electric field synergistic strategy, facilitating the development of high-performance non-volatile memory.