Flexible, Fatigue-Free, and Large-Scale Bi_3.25La_0.75Ti₃O₁₂ Ferroelectric Memories

Flexible, fatigue-free, large-scale, and nonvolatile memory is an emerging technological goal in a variety of fields, including electronic skins, wearable devices, and other flexible electronics. Perovskite oxide films deposited on rigid substrates (e.g., Si and SrTiO₃) at 500-700 °C and >1.0 Pa oxygen ambience have been widely used in electronic industries. However, their applications in flexible electronics are challenging, if not impossible. Here, the Bi_3.25La_0.75Ti₃O₁₂ ferroelectric films with SrRuO₃ or Pt electrodes were prepared on the two-dimensional mica substrates, and then the flexible Pt/SrRuO₃/Bi_3.25La_0.75Ti₃O₁₂/Pt memories have been achieved through reducing the mica to ∼10 μm thickness. These memories show the saturated polarization of P_s ∼ 20 μC/cm², and either the <1% bending strain or a normal light illumination hardly overcomes the potential barrier among different polarizations which originate from the noncentral symmetry of the atomic structure. As a result, they can undergo 10⁹ write/erase cycles and/or 10000 times bending with 1.4 mm in radius without any fatigue or damage. Furthermore, they can withstand the operation at 20-200 °C or under light illumination. In short, these flexible oxide memories provide comprehensive performance for industrial applications.