High-temperature dielectric responses of molecularly-thin titania nanosheet

Abstract

We have investigated high-temperature dielectric properties of titania nanosheet (Ti_0.87O₂), a new class of high-κ nanomaterials derived from the exfoliation of layered compounds. In-situ characterizations using atomic force microscopy indicate a robust insulating property in a monolayer form of Ti_0.87O₂ nanosheets even at 200°C. Furthermore, layer-by-layer assembled nanocapacitors exhibit both size-free high-ε_r characteristic (~120) and high insulation resistance (~10⁻⁷ A/cm²) at high temperatures up to 250°C. The simultaneous improvement of ε_r and thermal stability in high-κ nanodielectrics is of critical importance for applications of high-temperature capacitors.