Ion Migration Studies in 2D Molybdenum Trioxide Thin Flake through Ionic Liquid Gating

Ionic liquid is well known for its ability to electrostatically enhance the carrier densities of devices and thin films. The formation of an electric double layer can electrostatically induced charge carriers and/or intercalate ions in and out of the lattice which can induce a large change of the electronic and optical properties and even crystal structures. We present a systematic study on exfoliated molybdenum trioxide devices regarding the property changes and the underlying ion migration during the biasing process through ionic liquid. A close to nine orders of magnitude modulation of the MoO$_{\mathrm{3}}$ conductivity was obtained via ionic liquid gating. Two types of ionic liquids are involved and rapid on/off switching can be realized through the lithium containing ionic liquid. Secondary ion mass spectrometry investigation is performed which reveals the ion migration details.