Postsynthesis of h‐BN/Graphene Heterostructures Inside a STEM

Abstract

Combinations of 2D materials with different physical properties can form heterostructures with modified electrical, mechanical, magnetic, and optical properties. The direct observation of a lateral heterostructure synthesis is reported by epitaxial in‐plane graphene growth from the step‐edge of hexagonal BN (h‐BN) within a scanning transmission electron microscope chamber. Residual hydrocarbon in the chamber is the carbon source. The growth interface between h‐BN and graphene is atomically identified as largely N–C bonds. This postgrowth method can form graphene nanoribbons connecting two h‐BN domains with different twisting angles, as well as isolated carbon islands with arbitrary shapes embedded in the h‐BN layer. The electronic properties of the vertically stacked h‐BN/graphene heterostructures are investigated by electron energy‐loss spectroscopy (EELS). Low‐loss EELS analysis of the dielectric response suggests a robust coupling effect between the graphene and h‐BN layers.

A novel h-BN–RGO hybrids for epoxy resin composites achieving enhanced high thermal conductivity and energy density

“…All the peaks of the B, N and C-K edge have been reported in the literature. 23 Therefore, the h-BN-RGO particles have been prepared successfully.…”

Synthesis, structure and applications of graphene-based 2D heterostructures

“…Even though there is a slight mismatch on the crystal lattice of graphene and h-BN (~ 1.7 %), STM and HR-TEM studies indicated that it is possible to achieve a seamless stitching at atomic scale between both (Figure 15b). [33][34][35] The two lattices are then oriented, with the junctions corresponding predominantly to zigzag edges. TEM inspections also showed evidences of hybridization, with bonding occurring between the N atoms of the h-BN and the C atoms of the graphene.…”

Electron energy loss spectroscopy of excitons in two-dimensional-semiconductors as a function of temperature

“…[9][10][11] Recent results have shown that EELS at much higher spectral resolution (at or below 20 meV) and at high spatial resolution is possible. 7,[12][13][14] In this letter, we discuss the influence of sample temperature for excitons absorption measurements in TMD using EELS. We show that for MoSe 2 , the two exciton peaks separated by 220 meV are only distinguishable below 220 K and clearly visible at 150 K (for the same experimental conditions).…”