Quasiliquid Layer Promotes Hexagonal Boron Nitride (h-BN) Single-Domain Growth: h-BN on Pt(110)

Abstract

Hexagonal boron nitride (h-BN) monolayers were grown on Pt(110) using borazine as a precursor molecule. The resulting surface structure was studied by scanning tunneling microscopy, low-energy electron diffraction, and density functional theory calculations. Borazine fragments reduce the roughening temperature of pristine Pt(110) (T r = 1090 K); consequently, growth below T = 1100 K results in a serrated h-BN/Pt(110) surface with small terraces, defects, and domain boundaries. Surprisingly, h-BN deposition at T > 1100 K yields large terraces covered by a carpet-like single-domain h-BN monolayer. Despite the incommensurability and different symmetry, the epitaxial growth is almost perfect. The key to this counterintuitive behavior is the "soft" Pt(110) surface responding to the h-BN overlayer in two ways: First, the (1 × 2)missing-row (m.r.) reconstruction is converted into a (1 × n)-m.r. reconstruction with a regular alternation of n = 5 and 6, yielding a superperiodicity of the Moirépattern. Second, the remaining rows experience significant relaxations. Some Pt surface atoms are mobile underneath the h-BN monolayer, even at room temperature. Under growth conditions, the top metal layer is disordered and highly mobile, rendering the h-BN growth comparable to that on liquid gold. Such a mechanism may be of general relevance for the epitaxial growth of 2D materials. Because epitaxial deposition of Pt(110) on various substrates has been demonstrated, the present system appears scalable, and its regular 1D grooves render it a promising template for nanowire arrays.

2D Boron Nitride Nanosheets for Smart Thermal Management and Advanced Dielectrics

“…To enhance the practical applications of polymer/BNNS nanocomposites, the mass production of BNNSs in industrial scale is prerequisite. Therefore, tremendous efforts have been devoted to potentially scalable production of BNNS via various methods, such as mechanical force-assisted exfoliation, [28,46] liquidphase exfoliation, [2,31,32,47,48] gas-assisted exfoliation, [34,35,49] and CVD [50,51] methods. Herein, this section mainly presents the latest advancements of the above preparation methods, and the advantages and disadvantages and the preparation mechanism for each method are summarized and analyzed, respectively.…”

“…Chemical vapor deposition (CVD), as a common "bottom-up" approach, provides a platform to synthesize wafer-scale BN films by chemical reactions. [50,51,[73][74][75][76] The as-prepared BN films can be widely applied in the area of transparent optoelectronics, dielectric semiconductors, and flexible electronics. Inspired by this, some researchers utilized the controllable CVD techniques to fabricate ultrathin 2D h-BN film on various substrates (e.g., metals and insulators) and achieve device fabrication and applications.…”

Building Functional Memories and Logic Circuits with 2D Boron Nitride

“…[ 87 ] Recently, liquid Pt and Au surfaces have enabled the growth of large‐scale self‐assembly h‐BN films to be seamless and boundary‐free. [ 88,89 ] Since the Pt atoms diffuse surprisingly quickly at high growth temperatures, the elastic energies during growth are released by the appearance of regularly arranged boundary domains. At a high growth temperature, the h‐BN lattice is converted into a succession of (1 × 5) and (1 × 6) reconstructions along the [001] direction on the Pt (110) surfaces, leading to periodic stripes of the so‐called Moiré pattern.…”

Evolution of ordered nanoporous phases during h-BN growth: controlling the route from gas-phase precursor to 2D material by in situ monitoring

“…Most studies report completed overlayer structures while the complexity and individual steps, as illustrated in Figure 1, are often ignored. In particular, previous h-BN studies using real space methods [24][25][26][27] concentrate on local order in completed h-BN structures, while reciprocal space studies [28][29][30] have provided information about long-range order. 31 In this paper we present a systematic analysis, at various temperatures beyond the ones reported for best growth conditions (1050-1100 K 24,26,29 ) and at various dosing rates.…”