Lateral heterostructures of two-dimensional materials by electron-beam induced stitching

Abstract

We present a novel methodology to synthesize two-dimensional (2D) lateral heterostructures of graphene and MoS2 sheets with molecular carbon nanomembranes (CNMs), which is based on electron beam induced stitching. Monolayers of graphene and MoS2 were grown by chemical vapor deposition (CVD) on copper and SiO2 substrates, respectively, transferred onto gold/mica substrates and patterned by electron beam lithography or photolithography. Self-assembled monolayers (SAMs) of aromatic thiols were grown on the gold film in the areas where the 2D materials were not present. An irradiation with a low energy electron beam was employed to convert the SAMs into CNMs and simultaneously stitching the CNM edges to the edges of graphene and MoS2, therewith forming a heterogeneous but continuous film composed of two different materials. The formed lateral heterostructures possess a high mechanical stability, enabling their transfer from the gold substrate onto target substrates and even the preparation as freestanding sheets. We characterized the individual steps of this synthesis and the structure of the final heterostructures by complementary analytical techniques including optical microscopy, Raman spectroscopy, atomic force microscopy (AFM), helium ion microscopy (HIM), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM) and find that they possess nearly atomically sharp boundaries.

Supported and Suspended 2D Material-Based FET Biosensors

“…Numerous techniques for patterning of 2D materials have been recognized in the past decades [14][15][16]22,43]. It has just begun to apply a photolithography technique, electron beam lithography, and scanning probe technique for patterning 2D films [44][45][46][47]. Shortly the market for 2D materials is expected to compete with the reliability of silicon-based electronic sensor because of possibility of designing in micro and nanoscale.…”

Selective ion sieving through arrays of sub-nanometer nanopores in chemically tunable 2D carbon membranes

“…The transfer procedure was conducted as described elsewhere. 31 A PMMA layer (100 nm, 50 kDa, All-Resist, AR-P 671.04) was spin coated onto the CNM on gold/mica and hardened for 10 min at 90°C. Subsequently, a thicker layer of PMMA (200 nm, 950 kDa, All-Resist, AR-P 679.04) was spin coated on top of the first one and hardened for 10 min at 90°C.…”

Non-cytotoxic carbon nanocapsules synthesized via one-pot filling and end-closing of multi-walled carbon nanotubes

“…[5,7,19] New properties and applications arise from the creation of van der Waals heterostructures of layered compounds. [43,44] _ENREF_44…”