High-Throughput Ellipsometric Contrast Microscopy of Lateral 2D Heterostructures for Optoelectronics.

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Covalently-bonded lateral 2D heterostructures offer unique optoelectronic properties but uncontrolled junction placement hinders device integration.
• Current methods require post-growth identification of heterojunctions, limiting high-throughput characterization.

Purpose of the Study:

• To demonstrate ellipsometric contrast microscopy (ECM) for rapid, high-contrast imaging of 2D lateral heterostructures.
• To develop a computer vision algorithm for precise identification and integration of heterostructure junctions.

Main Methods:

• Utilized ellipsometric contrast microscopy (ECM) for imaging MoSe2-WSe2 and MoS2-WS2 lateral heterostructures.
• Developed and applied a computer vision algorithm for junction identification and device integration.

Main Results:

• ECM enabled rapid, high-material-contrast imaging of 2D lateral heterostructures down to sub-nanometer thickness.
• Computer vision algorithm precisely identified monolayer heterostructure junctions.
• Demonstrated integration of identified junctions into rectifying devices and photodetectors.

Conclusions:

• ECM is advantageous for reliable, fast characterization of atomically thin 2D heterostructures.
• This approach facilitates large-scale integration into advanced optoelectronic devices.
• Potential for extension to characterization of other nanomaterials.