SZFI Hírek

The composition and structure of the ubiquitous hydrocarbon contamination on van der Waals materials

A. Pálinkás, G. Kálvin, P. Vancsó, K. Kandrai, M. Szendrő, G. Németh, M. Németh, Á. Pekker, J.S. Pap, P. Petrik, K. Kamarás, L. Tapasztó, P. Nemes-Incze
Nature Communications 13 6770/1-10 oldal

© Nature Commun.

The behavior of single layer van derWaals (vdW) materials is profoundly

influenced by the immediate atomic environment at their surface, a prime

example being the myriad of emergent properties in artificial heterostructures.

Equally significant are adsorbates deposited onto their surface

from ambient. While vdW interfaces are well understood, our knowledge

regarding atmospheric contamination is severely limited. Here we show that

the common ambient contamination on the surface of: graphene, graphite,

hBN and MoS2 is composed of a self-organized molecular layer, which forms

during a few days of ambient exposure. Using low-temperature STM measurements

we image the atomic structure of this adlayer and in combination

with infrared spectroscopy identify the contaminant molecules as normal

alkanes with lengths of 20-26 carbon atoms. Through its ability to self-organize,

the alkane layer displaces the manifold other airborne contaminant

species, capping the surface of vdW materials and possibly dominating their

interaction with the environment.

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Beküldte: Kamarás Katalin, 2022. 11. 24. 09.43,   Hír típusa: Cikk,   Megtekintve: 259 alkalommal