Experimental demonstration of continuous electronic structure tuning via strain in atomically thin MoS2

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Atomically thin molybdenum disulfide (MoS2) is a promising two-dimensional material with unique electronic and optical properties.
• Flexible electronics and optoelectronics require materials whose properties can be dynamically controlled on non-rigid substrates.

Purpose of the Study:

• To investigate the effect of uniaxial tensile strain on the electronic structure of MoS2 on flexible substrates.
• To quantify the tuning rate of electronic transitions under strain.

Main Methods:

• Applying controlled uniaxial tensile strain to atomically thin MoS2 films on flexible substrates.
• Utilizing absorption and photoluminescence spectroscopy to probe electronic transitions.
• Performing first-principles calculations to validate experimental findings.

Main Results:

• Demonstrated continuous tuning of the electronic structure of MoS2 via tensile strain.
• Quantified redshift rates for direct gap transitions (~70 meV/%) and indirect gap transitions (~1.6 times larger).
• Achieved excellent agreement between experimental spectroscopy data and theoretical calculations.

Conclusions:

• Uniaxial tensile strain effectively tunes the electronic and optical properties of MoS2 on flexible substrates.
• The observed strain-induced tuning highlights the potential of 2D materials for advanced flexible devices.
• This work provides a pathway for designing strain-tunable optoelectronic devices using 2D crystals.