Growth temperature dependent graphene alignment on Ir(111)

Hichem Hattab (1) , Alpha T. N'Diaye (2) , Dirk Wall (1) , G. Jnawali (1) , Johann Coraux (3) , Carsten Busse (2) , Raoul van Gastel (4) , Bene Poelsema (4) , Thomas Michely (2) , Frank-J. Meyer zu Heringdorf (1) , Mickael Horn von Hoegen (1)

1 Institut für Experimentelle Physik
2 II. Physikalisches Institut [Köln]
3 NEEL - Quan2m - Interactions modulables dans des états quantiques 2D
4 MESA + Institute for Nanotechnology

The morphology of graphene monolayers on Ir(111) prepared by thermal decomposition of ethylene between 1000 and 1530 K was studied with high resolution low energy electron diffraction. In addition to a well-oriented epitaxial phase, randomly oriented domains are observed for growth temperatures between 1255 and 1460 K. For rotational angles of ±3° around 30° these domains lock-in in a 30° oriented epitaxial phase. Below 1200 K the graphene layer exhibits high disorder and structural disintegrity. Above 1500 K the clear moiré spots reflect graphene in a single orientation epitaxial incommensurate phase.

Mots clés: graphene; iridium; CVD; SPALEED

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Hichem Hattab, Alpha T. N'Diaye, Dirk Wall, G. Jnawali, Johann Coraux, et al.. Growth temperature dependent graphene alignment on Ir(111). Applied Physics Letters, 2011, 98, pp.141903. ⟨10.1063/1.3548546⟩. ⟨hal-00587437⟩