Dielectric Constant of a Single MoO<sub>3</sub> Nanostructure.

Gu, Minji; Kim, Taewoong; Lee, Dongjae; Park, Jiyu; Kim, Taekyeong · Nano Lett · 2025

basic_science · Level V

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Abstract

MoO<sub>3</sub> is a promising transition metal oxide due to its high dielectric constant (κ) and multifunctionality in electronic and optoelectronic applications. Oxidation-induced nanoscale MoO<sub>3</sub>, synthesized via oxidation scanning probe lithography (o-SPL) of MoS<sub>2</sub>, requires in-depth characterization of its dielectric properties. In this study, we measured the κ of a single MoO<sub>3</sub> nanostructure, which was confirmed to be in the amorphous phase through water solubility tests and high-resolution transmission electron microscopy (HRTEM). Using electrostatic force microscopy (EFM) and numerical calculations, we determined a high κ value of approximately 25, nearly six times higher than that of SiO<sub>2</sub>. Additionally, nanoscale κ imaging revealed that the κ of MoO<sub>3</sub> nanostructures is independent of their size. These findings suggest that oxidation-induced MoO<sub>3</sub> nanostructures are promising candidates as high-κ dielectric materials for future nanoscale devices.