Epitaxial growth of a single-domain hexagonal boron nitride monolayer.
We investigate the structure of epitaxially grown hexagonal boron nitride (h-BN) on Ir(111) by chemical vapor deposition of borazine. Using photoelectron diffraction spectroscopy, we unambiguously show that a single-domain h-BN monolayer can be synthesized by a cyclic dose of high-purity borazine onto the metal substrate at room temperature followed by annealing at T=1270 K, this method giving rise to a diffraction pattern with 3-fold symmetry. In contrast, high-temperature borazine deposition (T=1070 K) results in a h-BN monolayer formed by domains with opposite orientation and characterized by a 6-fold symmetric diffraction pattern. We identify the thermal energy and the binding energy difference between fcc and hcp seeds as key parameters in controlling the alignment of the growing h-BN clusters during the first stage of the growth, and we further propose structural models for the h-BN monolayer on the Ir(111) surface.
Physics Department, University of Trieste , Via Valerio 2, 34127 Trieste, Italy.
Fabrizio
F
Orlando
Paolo
P
Lacovig
Luca
L
Omiciuolo
Nicoleta G
NG
Apostol
Rosanna
R
Larciprete
Alessandro
A
Baraldi
Silvano
S
Lizzit
Ir(111); X-ray photoelectron diffraction; chemical vapor deposition; hexagonal boron nitride; temperature-programmed growth