Doping and Field Effect in Novel 2D Layered Oxides*

Layered transition metal oxides remain a relatively unexplored front in the study of 2D van der Waals materials, providing opportunities to further advance semiconductor physics and devices in a novel class of atomically thin crystals. It is usually challenging to dope these materials and achieve field effect control for applications like transistors, given their wide bandgaps. However, when the structure is altered via doping or intercalation, the bandgap and carrier concentration can also be affected, enabling gating behavior. In this talk, we will first introduce our study of doping multilayer nanoflakes of α-MoO3 by H⁺ ion intercalation, which creates oxygen vacancies and n-type doping. Devices were fabricated with typical electron densities in the range of 10¹⁵/cm² and field effect mobilities of 0.1-10 cm²/Vs. Predicted anisotropic in-plane transport effects were also observed. We may then discuss doping and field effect response in additional 2D layered oxides.