Scalable Design of Two-Dimensional Oxide Nanosheets for Construction of Ultrathin Multilayer Nanocapacitor

Large size of capacitors is the main hurdle in miniaturization of current electronic devices. Herein, a scalable solution-based layer-by-layer engineering of metallic and high-κ dielectric nanosheets into multilayer nanosheet capacitors (MNCs) with overall thickness of ≈20 nm is presented. The MNCs are built through neat tiling of 2D metallic Ru_0.95O₂^0.2− and high-κ dielectric Ca₂NaNb₄O₁₃⁻ nanosheets via the Langmuir–Blodgett (LB) approach at room temperature which is verified by cross-sectional high-resolution transmission electron microscopy (HRTEM). The resultant MNCs demonstrate a high capacitance of 40–52 µF cm⁻² and low leakage currents down to 10⁻⁵–10⁻⁶ A cm⁻². Such MNCs also possess complimentary in situ robust dielectric properties under high-temperature measurements up to 250 °C. Based on capacitance normalized by the thickness, the developed MNC outperforms state-of-the-art multilayer ceramic capacitors (MLCC, ≈22 µF cm⁻²/5 × 10⁴ nm) present in the market. The strategy is effective due to the advantages of facile, economical, and ambient temperature solution assembly.