This project will involve growth and characterization of two-dimensional (2D) semiconducting heterostructures that are atomically thin and exhibit strong bonding within layers and weak interaction between layers. 2D semiconducting heterostructures provide unparalleled opportunities for applications in optoelectronics, spintronics, energy harvesting devices, flexible electronics, etc.  The weak interlayer interaction allows for the formation of vertical heterostructures of dissimilar materials, whereas in lateral heterostructures different 2D constituents are stitched together with strong bonding. We recently demonstrated a novel method to induce the phase transformation of a transition metal dichalcogenide (TMD) from semiconductor to topological insulator (insulating in the interior but conductive on the edges) via the construction of lateral core-shell architecture.  During the 10-week program, the student, together with a graduate mentor, will conduct heterostructure growth by molecular beam epitaxy and investigate emergent phenomena arising from the proximity coupling in heterostructures using scanning tunneling microscopy/spectroscopy techniques.   

Scientific goals:   

• Understand the mechanisms of proximity coupling and engineer 2D materials’ phase and properties in heterostructures

Student learning goals:

• Gain experience on thin film growth by molecular beam epitaxy and characterization by scanning tunneling microscopy/spectroscopy
• Understand semiconductor physics and the influences of defects, grain boundaries, and Moiré patterns on electronic structures of heterostructures