Robust Excitons and Trions in Monolayer MoTe2

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Molybdenum telluride (MoTe2) is a 2D transition metal dichalcogenide semiconductor with unique electronic properties.
• Strong spin-orbit coupling and a small energy gap in MoTe2 enable novel applications in valleytronic and excitonic devices.

Purpose of the Study:

• To demonstrate the electrical modulation of excitons in monolayer MoTe2.
• To accurately measure the binding energies of charged and neutral excitons in this material.

Main Methods:

• Photoluminescence spectroscopy was employed to observe and analyze excitons.
• Photoluminescence excitation spectroscopy was used to determine exciton binding energies.
• Theoretical calculations were performed to validate experimental findings.

Main Results:

• Electrical modulation of negatively charged (X(-)), neutral (X(0)), and positively charged (X(+)) excitons in monolayer MoTe2 was successfully achieved.
• The binding energies for X(+) and X(-) excitons were measured to be approximately 24 meV and 27 meV, respectively.
• The exciton binding energy of monolayer MoTe2 was determined to be 0.58 ± 0.08 eV, aligning well with the calculated value of 0.64 eV.

Conclusions:

• Electrical control over different types of excitons in monolayer MoTe2 is feasible.
• The measured exciton binding energies provide crucial data for designing MoTe2-based excitonic devices.
• This research contributes to the understanding and application of 2D materials in advanced electronic devices.