Selective-area heteroepitaxial growth of h -BN micropatterns on graphene layers

Abstract

We report the selective-area heteroepitaxial growth of hexagonal boron nitride (h-BN) on graphene layers using catalyst-free chemical vapor deposition. For both catalyst-free and selective-area growth, exfoliated graphene layers were irradiated with a focused ion beam to generate nucleation sites on the inert graphene surface. A high-quality, ultrathin h-BN micropattern array was selectively grown only on the patterned region of graphene using borazine, ammonia, and nitrogen without any metal catalyst. The crystal structure and microstructural properties of h-BN grown on graphene were investigated using synchrotron radiation x-ray diffraction and transmission electron microscopy, respectively. The catalyst-free growth mechanism and heteroepitaxial relationship between h-BN and graphene layers are discussed.

Refractory Vertically Aligned Carbon Nanotube–Boron Nitride Nanocomposites for Scalable Electrical Anisotropic Interconnects

“…To verify these results, we compared them to the HRTEM of h-BN shown in Figure S10b. It demonstrates a similar graphene-like layered structure, with a layer thickness of roughly 3–4 Å, which is consistent with both shown in Figure b and reported results. ,, Combining this structural consistency and the elemental characterization provided by EELS and EDS, we are therefore positive that these graphene-liked layers outside the VACNT wall are h-BN. ,,, In addition, large h-BN nucleation sites were noted (dark round dots). The existence of these large spots is believed to correspond to the white features seen in the HAADF image (Figure e).…”

“…30,33,49 Combining this structural consistency and the elemental characterization provided by EELS and EDS, we are therefore positive that these graphene-liked layers outside the VACNT wall are h-BN. 36,39,50,51 In addition, large h-BN nucleation sites were noted (dark round dots). The existence of these large spots is believed to correspond to the white features seen in the HAADF image (Figure 3e).…”

“…Meanwhile, the electron conduction along the VACNTs was not affected. Overall, VACNTs provided highly aligned electrical conductive pathways while the infiltrated h-BN in the nanocomposites induced the significant difference in EPT along different directions, 50 which comprehensively yielded the highly anisotropic electrical conducting performance of the prepared VACNT-BN nanocomposites.…”

Nonvolatile Memories Based on Graphene and Related 2D Materials

“…Notable steps forward have been made in the growth of graphene on metals and on silicon carbide (SiC), although it is more difficult to exploit the latter process for NVM applications due to its ultimate size limitations and inability to be integrated in a Si‐flow process. Progress is also reported on the growth of h‐BN and TMD materials. However, the growth of large‐area monolayer or few‐layer single crystals of h‐BN and TMDs is still a major challenge that will require continued significant research efforts.…”

Substitutional mechanism for growth of hexagonal boron nitride on epitaxial graphene

“…Whereas the growth of h-BN on catalytic metal substrates has been studied by many groups, as recently reviewed by Yin et al, 12,13 the mechanism for h-BN growth directly on graphene (or EG) without any underlying metal is a less well understood topic. 14,15,16,17,18 Our growth of h-BN is accomplished by exposing the EG to borazine, (BH)3(NH)3, at a pressure of 1×10 -4 Torr and temperatures in the range 950 -1300 °C (see Supplementary Material for further details); 19,20 we focus here on results obtained at 1100 C. Characterization of the h-BN is performed in-situ using wide-area low-energy electron diffraction (LEED), both before and after growth, and ex-situ using atomic force microscopy (AFM), low-energy electron microscopy (LEEM) including selected-area LEED (1.25 m spatial resolution), and low-energy electron reflectivity (LEER).…”