Growth Kinetics of Two-Dimensional Hexagonal Boron Nitride Layers on Pd(111)

Abstract

Using in situ variable-temperature scanning tunneling microscopy (300− 673 K) during chemical vapor deposition of two-dimensional hexagonal boron nitride (hBN) on Pd(111) from borazine precursor at pressures up to 10 −6 mbar, we identify the mechanisms leading to carpetlike uphill or downhill growth across the Pd steps. Deposition at a higher rate and lower temperature promotes uphill growth via preferential attachment at the ascending and descending step-edges, whereas a lower deposition rate and higher temperature lead to downhill growth via nucleation and growth of islands on Pd terraces. We attribute this unusual growth behavior to differences in temperaturedependent rates of hBN deposition at the steps versus on the Pd terraces. Our results illustrate how growth mechanisms can be activated by a pair of parameters (substrate temperature and partial pressure of borazine) and provide new insights into the mechanisms underlying carpetlike growth of hBN and other layered materials.

Effects of the Substrate Structure on the CVD Growth of Two-Dimensional Hexagonal Boron Nitride

“…A high deposition rate at 1500 K leads to the formation of single-domain h-BN on the rough surface, which is comparable to the finding obtained by Arias et al 57 for h-BN on Pd (111). However, the size of the obtained crystal is smaller than the single crystal grown on the normal and vacancy-disordered Ni(111) surfaces.…”

Structure, Properties and Applications of Two‐Dimensional Hexagonal Boron Nitride

“…It is worth noting that the influences of surface steps on h-BN growth are not only observed on Cu, but also on Pd, Ir, Pt, Ru, Rh, etc. [14,[218][219][220][221] Controlling of the Number of Layers: While monolayer h-BN has been extensively used as growth templates, tunneling barriers, and atomic membranes, multilayer h-BN has a great demand for use as dielectric layers, dangling bond-free substrates, and strong membranes. [80] One of the first instances of multilayer h-BN (films of 5-50 nm) growth on Ni surfaces is reported by Shi et al [179] The h-BN film is grown in an atmospheric pressure CVD (APCVD) system, using polycrystalline Ni as a substrate and borazine vapor (B 3 N 3 H 6 ) carried out by N 2 gas flow as the precursor.…”

“…It is worth noting that the influences of surface steps on h‐BN growth are not only observed on Cu, but also on Pd, Ir, Pt, Ru, Rh, etc. [ 14,218–221 ]…”

Room-Temperature Emitters in Wafer-Scale Few-Layer Hbn by Atmospheric Pressure Cvd

“…Whereas there are other difficulties concerning the transfer method, which should ideally avoid the introduction of any further defects, impurities, or cracks. Several CVD precursors were proposed to grow hBN thin films: gaseous (e.g., boron trifluoride, boron trichloride, diborane and ammonia) [25], liquid (e.g., borazine, molten Fe 82 B 12 alloy) [26,27], and solid (e.g., ammonia borane -AB) [28]. Borazine is one of the most common precursors, due to its high vapor pressure.…”