Segregation-Enhanced Epitaxy of Borophene on Ir(111) by Thermal Decomposition of Borazine

Karim M. Omambac, Marin Petrović, Pantelis Bampoulis, Christian Brand, Marko A. Kriegel, Pascal Dreher, David Janoschka, Ulrich Hagemann, Nils Hartmann, Philipp Valerius, Thomas Michely, Frank J. Meyer Zu Heringdorf, Michael Horn-Von Hoegen*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

26 Citations (Scopus)


Like other 2D materials, the boron-based borophene exhibits interesting structural and electronic properties. While borophene is typically prepared by molecular beam epitaxy, we report here on an alternative way of synthesizing large single-phase borophene domains by segregation-enhanced epitaxy. X-ray photoelectron spectroscopy shows that borazine dosing at 1100 °C onto Ir(111) yields a boron-rich surface without traces of nitrogen. At high temperatures, the borazine thermally decomposes, nitrogen desorbs, and boron diffuses into the substrate. Using time-of-flight secondary ion mass spectrometry, we show that during cooldown the subsurface boron segregates back to the surface where it forms borophene. In this case, electron diffraction reveals a (6 × 2) reconstructed borophene χ6-polymorph, and scanning tunneling spectroscopy suggests a Dirac-like behavior. Studying the kinetics of borophene formation in low energy electron microscopy shows that surface steps are bunched during the borophene formation, resulting in elongated and extended borophene domains with exceptional structural order.

Original languageEnglish
Pages (from-to)7421-7429
Number of pages9
JournalACS nano
Issue number4
Publication statusPublished - 27 Apr 2021
Externally publishedYes


  • borophene
  • chemical vapor deposition
  • epitaxial growth
  • iridium
  • segregation
  • thermal catalytic decomposition
  • two-dimensional materials

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