One-dimensional van der Waals heterostructures

TL;DR

This paper introduces a novel class of one-dimensional van der Waals heterostructures, demonstrating coaxial stacking of different materials in nanotubes, expanding the design space beyond traditional 2D layered structures.

Contribution

It presents the concept and fabrication of 1D vdW heterostructures, enabling new nanotube materials with customizable properties beyond 2D limitations.

Findings

Demonstrated a 5 nm diameter nanotube with three different materials

Showed coaxial stacking of CNT, BNNT, and MoS2 nanotubes

Anticipated discovery of new semiconducting nanotube materials

Abstract

Property by design is one appealing idea in material synthesis but hard to achieve in practice. A recent successful example is the demonstration of van der Waals (vdW) heterostructures,1-3 in which atomic layers are stacked on each other and different ingredients can be combined beyond symmetry and lattice matching. This concept, usually described as a nanoscale Lego blocks, allows to build sophisticated structures layer by layer. However, this concept has been so far limited in two dimensional (2D) materials. Here we show a class of new material where different layers are coaxially (instead of planarly) stacked. As the structure is in one dimensional (1D) form, we name it "1D vdW heterostructures". We demonstrate a 5 nm diameter nanotube consisting of three different materials: an inner conductive carbon nanotube (CNT), a middle insulating hexagonal boron nitride nanotube (BNNT) and an outside semiconducting MoS2 nanotube. As the technique is highly applicable to other materials in the current 2D libraries,4-6 we anticipate our strategy to be a starting point for discovering a class of new semiconducting nanotube materials. A plethora of function-designable 1D heterostructures will appear after the combination of CNTs, BNNTs and semiconducting nanotubes.