Rotationally Controlled van der Waals Heterostructures: Electronics Properties and Device Applications
Heterostructures consisting of two-dimensional (2D) materials such as graphene, transition metal dichalcogenides (TMDs), and hexagonal boron nitride (hBN) have gained increased scrutiny in recent years for their fundamental properties, and potential applications. Unlike epitaxially grown heterostructures, where the crystal orientation of different layers in is set by the starting substrate, 2D material heterostructures realized using a layer-by-layer transfer are often rotationally misaligned, which in turn affects the interlayer coupling and is detrimental to the electronic properties of the heterostructure. Here we discuss recent advances in the realization of rotationally controlled heterostructures, and explore their electronic properties and applications. In rotationally aligned double bilayer graphene heterostructures we demonstrate resonant tunneling, and high performance interlayer tunneling field-effect transistors with high ON current, and high ON/OFF ratio at room temperature. In rotationally misaligned heterostructures, we show that a controlled twist between individual layers can be used to engineer new energy bands associated with the underlying moiré crystal. We use small twist angle bilayer graphene as an example to realize, and explore the electron transport in such moiré crystals, and discuss potential applications of these artificial crystals.
|Rotationally Controlled van der Waals Heterostructures: Electronics Properties and Device Applications|
Tuesday, March 21, 2017, 4 p.m.–5 p.m. ET
Durham, NC, United States