Dresden 2026 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 33: Graphene: Growth, structure and substrate interaction (joint session O/HL)

O 33.6: Vortrag

Dienstag, 10. März 2026, 12:00–12:15, HSZ/0201

Subsurface carbon controls graphene growth on Ir(111) — •Smruti Ranjan Mohanty, Lothar Brendel, Marko Kriegel, Niels Ganser, Frank-Joachim Meyer zu Heringdorf, and Michael Horn-von Hoegen — Faculty of Physics, University of Duisburg-Essen, 47057 Duisburg, Germany

The CVD growth of 2D materials is governed by a balance between adsorption, surface diffusion, and nucleation. For transition metal substrates, dissolution into the bulk acts as an additional parameter. By employing in-operando low-energy electron microscopy (LEEM) to monitor graphene growth on Ir(111), the effect of the growth temperature and the precursor pressure on the nucleation behavior is studied. The island nucleation density exhibits two distinct regimes, described as separate cases within Venables nucleation theory [1]. For a critical nucleus size i* = 5, low dosing pressures yield a low nucleation density that is governed by incomplete condensation with a scaling exponent of 2.5. At higher-dosing pressures, adsorptions at island edges dominate over the adatoms loss into the substrate, resulting in a higher nucleation density and a strongly reduced scaling exponent. Kinetic Monte Carlo simulations that incorporate bulk dissolution reveal both nucleation regimes and find a universal, temperature-independent scaling law. The results indicate a universal nucleation behavior for 2D materials with finite, non-negligible solubility in the supporting metal substrate.

[1] J A Venables et al 1984 Rep. Prog. Phys. 47 399

Keywords: Graphene; Ir(111); Chemical vapor deposition; Low-energy electron microscopy (LEEM); kinetic Monte Carlo simulations