Regensburg 2025 – scientific programme
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O: Fachverband Oberflächenphysik
O 37: Poster 2D Materials Beyond Graphene: Growth, Structure and Substrate Interaction (joint session O/HL)
O 37.5: Poster
Tuesday, March 18, 2025, 13:30–15:30, P3
UHV-CVD on Ir(111) for the Growth of 2D Materials — •Niels Ganser1, Marko Kriegel1, Karim Omambac1, Marin Petrovic2, Christian Brand1, Steffen Franzka3, Birk Finke1, Tobias Hartl4, Thomas Michely4, Frank-Joachim Meyer zu Heringdorf1, and Michael Horn-von Hoegen1 — 1Universität Duisburg-Essen — 2Institute of Physics, Zagreb — 3ICAN, Duisburg — 4Universität zu Köln
Hexagonal boron nitride (hBN) can be grown by scalable chemical vapor deposition (CVD) from a borazine B3N3H6 precursor. Here we show that the hBN quality depends strongly on the growth temperature Tg and the dosing pressure p.
Combined SPA-LEED and LEEM measurements show a strong dependence of n on p. We find that the quality of the hBN layers that can be achieved by increasing Tg is limited by the process of disintegration of the borazine at Tg> 950 ∘C resulting in growth of borophene (2D Boron) instead [1]. Thus, it is possible to selectively grow either hBN or borophene from the same precursor [2].
Corroborating SPA-LEED measurements reveal a negative thermal expansion coefficient of α = (−2.4 ± 1.2) × 10−6 K−1 for 2D hBN in the temperature regime between 700 and 1100 ∘C. This finding can be explained by Lifshitz’ membrane effect [3].
[1] Lifshitz, I., Zh. Eksp. Teor. Fiz. 22, 475 (1952)
[2] Omambac, K. et al., ACS Nano 15, 7421 (2021)
[3] Omambac, K. et al., ACS Nano 17, 17946 (2023)
Keywords: hexagonal boron nitride; chemical vapor deposition; selective growth