posted on 2017-03-16, 00:00authored byOkan Deniz, Carlos Sánchez-Sánchez, Tim Dumslaff, Xinliang Feng, Akimitsu Narita, Klaus Müllen, Neerav Kharche, Vincent Meunier, Roman Fasel, Pascal Ruffieux
The electronic properties
of graphene nanoribbons grown on metal substrates are significantly
masked by the ones of the supporting metal surface. Here, we introduce
a novel approach to access the frontier states of armchair graphene
nanoribbons (AGNRs). The in situ intercalation of Si at the AGNR/Au(111)
interface through surface alloying suppresses the strong contribution
of the Au(111) surface state and allows for an unambiguous determination
of the frontier electronic states of both wide and narrow band gap
AGNRs. First-principles calculations provide insight into substrate
induced screening effects, which result in a width-dependent band
gap reduction for substrate-supported AGNRs. The strategy reported
here provides a unique opportunity to elucidate the electronic properties
of various kinds of graphene nanomaterials supported on metal substrates.