Atom-Scale Engineering of Synthetic Layered Materials

Materials engineered with atomic precision promise unprecedented control over their structure and properties, with profound implications for novel physics and future device technologies. Atomically thin two-dimensional (2D) materials provide a versatile platform for atom-scale engineering: they exhibit a variety of superlative electronic characteristics, and their discrete layered structures and van der Waals (vdW) interlayer bonding enable them to be grown, patterned, and stacked to generate heterostructured solids with atomically precise vertical composition. Additionally, their lateral band structure can be tailored by the formation of moiré superlattices between layers to realize novel quantum phases. In this talk, I will discuss advances in two areas related to the goal of atom-scale engineering via 2D materials:

(1) Looking beyond 2D materials derived from layered vdW solids (e.g., graphene from graphite), I will present the growth of 2D boron sheets (i.e., borophene) – a synthetic 2D material which exhibits metallic, ordered-vacancy atomic structures distinct from the semiconducting bulk boron allotropes.

(2) Current approaches for stacking 2D layers into vdW heterostructures are slow, stochastic, and artisanal. I will discuss the development of automated manufacturing of vdW heterostructures with unprecedented speed, patternability, and angle control. Fabrication using multilayered, microstructured polymeric effectors under high vacuum enables repeatable assembly of wafer-scale grown material. Additionally, stacking with single crystal, monolayer source material enables the fabrication of twisted n-layer heterostructures, with n limited only by the size of the source crystal, providing unprecedented opportunities for moiré engineering.