Naslov
Step-induced faceting and related electronic effects for graphene on Ir(332)

Autori
Šrut Rakić, Iva ; Kralj, Marko ; Jolie, Wouter ; Lazić, Predrag ; Sun, Wenhao ; Avila, Hose ; Asensio, Maria-Carmen ; Craes, Fabian ; Mikšić Trontl, Vesna ; Busse, Carsten ; Pervan, Petar

Izvornik
Carbon (0008-6223) 110 (2016); 267-277

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
graphene ; stepped surface ; electronic properties ; angle-resolved photoemission spectroscopy ; scanning tunneling microscopy

Sažetak
Modifications of graphene's electronic band structure can be achieved through periodic bending strain and related potential in samples grown on stepped substrates, opening a viable route to implement the periodicity effects in this ultimate two-dimensional (2D) material. We studied graphene grown on stepped Ir(332), which can be benchmarked to a well-known graphene on flat Ir(111) recognized for a weak van der Waals (vdW) interaction. The structural characterization indicated that graphene growth induces reversible, well defined faceting of iridium surface into alternating terraces and step bunches, while spectroscopy techniques revealed substantial changes of graphene's electronic structure. Crucially, highly concentrated Ir step edges, resulting in locally strong chemical bonding of graphene, introduce a dominant energy parameter which overwhelms the induced strain and presents a driving force for the surface faceting. This sets a general framework for the understanding of graphene mediated faceting of stepped substrates whenever the corresponding low index surface exhibits dominantly vdW interaction with graphene, which can be also supplemented to other 2D materials. Interestingly, the graphene p band becomes pronouncedly anisotropic due to the presence of a periodic potential originating from steps, and lateral variation of the charge carrier concentration enabling a straightforward electronic band engineering in graphene.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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