M-S. Khan, H-J. Kim, Y-H. Kim, Y. Ebina, W. Sugimoto, T. Sasaki, M. Osada: “Scalable design of two‐dimensional oxide nanosheets for construction of ultrathin multilayer nanocapacitors”, Small, 16, 2003485 (2020).
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 Ru0.95O20.2− 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.