Epitaxial Growth of Hexagonal Boron Nitride on Ir(111)

• Published in: Journal of physical chemistry. C 2012-01, Vol.116 (1), p.157-164
• Main Authors: Orlando, Fabrizio, Larciprete, Rosanna, Lacovig, Paolo, Boscarato, Ilan, Baraldi, Alessandro, Lizzit, Silvano
• Format: Article
• Language: English
• Subjects: C: Nanops and Nanostructures; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electron diffraction and scattering; Exact sciences and technology; Low-energy electron diffraction (leed) and reflection high-energy electron diffraction (rheed); Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Solid surfaces and solid-solid interfaces; Structure and morphology; thickness; Structure of solids and liquids; crystallography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of film growth; Thin film structure and morphology
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp207571n

The formation of a hexagonal boron nitride (h-BN) layer through dissociation of borazine (B3N3H6) molecules on Ir(111) has been investigated by a combination of X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure, temperature-programmed desorption, and low-energy electron diffraction. At low temperature (T = 170 K), molecular borazine adsorption occurs with the plane of the benzene-like ring parallel to the substrate. Dehydrogenation is observed at temperatures higher than 250 K and extends up to 900 K, with a maximum H2 desorption rate around 300 K. Besides dehydrogenation, room temperature adsorption of borazine leads to the formation of atomic and molecular fragments due to the break-up of part of the BN bonds. The epitaxial growth of h-BN starts at temperature higher than 1000 K where an extended and long-range ordered layer is obtained. The presence of a corrugation in the h-BN layer with moiré periodicity of (13 × 13)/(12 × 12) BN/Ir unit cell is reflected in the double component structure of the B 1s and N 1s core level spectra.