Precise Layer Control of MoTe(2) by Ozone Treatment

Transition metal dichalcogenides (TMDCs) demonstrate great potential in numerous applications. However, these applications require a precise control of layer thickness at the atomic scale. In this work, we present an in-situ study of the self-limiting oxidation process in MoTe(2) by ozone (O(3)) treatment. A precise layer-by-layer control of MoTe(2) flakes can be achieved via multiple cycles of oxidation and wet etching. The thinned MoTe(2) flakes exhibit comparable optical properties and film quality to the pristine exfoliated ones. Besides, an additional p-type doping is observed after O(3) oxidation. Such a p-doping effect converts the device properties of MoTe(2) from electron-dominated to hole-dominated ambipolar characteristics.