Precise Layer Control of MoTe₂ by Ozone Treatment

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Transition metal dichalcogenides (TMDCs) are promising materials for advanced applications.
• Precise control over TMDC layer thickness is crucial for optimizing device performance.
• Existing methods for thinning TMDCs can be challenging and lack atomic-scale precision.

Purpose of the Study:

• To investigate the self-limiting oxidation of molybdenum ditelluride (MoTe2) using ozone (O3).
• To develop a method for achieving atomic-scale layer thickness control in MoTe2 flakes.
• To analyze the impact of oxidation and thinning on MoTe2 properties.

Main Methods:

• In-situ study of MoTe2 oxidation using ozone (O3) treatment.
• Layer-by-layer thinning via multiple cycles of oxidation and wet etching.
• Characterization of optical properties and film quality of thinned MoTe2 flakes.

Main Results:

• Demonstrated self-limiting oxidation of MoTe2 with O3.
• Achieved precise layer-by-layer thinning of MoTe2 flakes.
• Thinned MoTe2 flakes retained comparable optical properties and film quality to pristine flakes.
• Observed p-type doping effect in MoTe2 after O3 oxidation.

Conclusions:

• Self-limiting oxidation offers a viable route for atomic-scale thickness control of MoTe2.
• Ozone treatment enables precise thinning while preserving material quality.
• The induced p-type doping modifies MoTe2 device characteristics, enabling hole-dominated ambipolar behavior.