Silicon intercalation at the interface of graphene and Ir(111)

Abstract

We report on the structural and electronic properties in the heterostructure of graphene/silicon/Ir(111). A (√19 × √19)R23.41° superstructure is confirmed by low energy electron diffraction and scanning tunneling microscopy and its formation is ascribed to silicon intercalation at the interface between the graphene and the Ir(111) substrate. The dI/dV measurements indicate that the interaction between graphene and Ir is effectively decoupled after silicon intercalation. Raman spectroscopy also reveals the vibrational states of graphene, G peak and 2D peak, which further demonstrates that the silicon-buffered graphene behaves more like intrinsic graphene.

Chemical gating of epitaxial graphene through ultrathin oxide layers

“…The first step to grow the Gr|SiO 2 |Ir(111) heterostructure is the intercalation of a few monolayers Si below graphene, which is achieved by evaporating silicon on the graphene/metal surface held at 720 K. 15,16 The bottom curves in Fig.1 show the C1s and Ir4f 7/2 spectra measured on the clean Gr/Ir(111) surface and after the intercalation of Si at 670 K. For the Gr/Ir(111) sample the C1s spectrum consists of a single narrow peak at 284.09 eV 17 and the Ir4f 7/2 spectrum exhibits the surface (S, 60.31 eV) and the bulk (B, 60.85 eV) components due to metal atoms in the first and in the lower crystal layers, respectively. 18 After the intercalation of 2.6 ML of Si the C1s spectrum shows a single component (C 1 , 284.25 eV) which has a similar intensity and is shifted by +160 meV with respect to the pristine spectrum.…”

Graphene–Silicon Layered Structures on Single‐Crystalline Ir(111) Thin Films

“…This behavior is in agreement with our previous work on the intercalated Si layer at the interface of graphene and Ir(111) single crystal. [14] In addition, we observed blue shifts of both G and 2D peaks with respect to that of pristine graphene, indicating a slight residual strain in graphene and charge transfer from the underlying Si layer. [20,21] Figure 4b shows XPS spectra of C 1s centered around 283.8 eV for graphene before and after the formation of graphene-silicon heterstructures, the characteristic features of sp 2 -hybridized C. The slight down shift (~0.2 eV) of the peak implies weaker charge transfer from the substrate to the graphene sheets.…”

“…[13,14] Such an approach produces graphene-silicon hetero-layered structures compatible with the current Si-based microelectronic techniques and is an obvious big step forward toward the fabrication and integration of graphene-based devices. Taking advantage of these techniques, the low cost preparation of graphene-silicon hetero-layered structures on single-crystalline metal films rather than on metal bulks is highly promising for applications in future microelectronic devices.…”

“…[8][9][10] Moreover, in order to weaken the interactions of graphene with its metal host, which may result in a suppression of the intrinsic properties of graphene, [11,12] the method of element intercalation of semiconductors at the interface between an epitaxial graphene layer and a transition metal substrate has been successfully realized. [13][14][15][16] In particular, intercalation of a silicon layer has aroused a great interest in this research direction.…”

Probing Electronic Properties of Graphene on the Atomic Scale by Scanning Tunneling Microscopy and Spectroscopy

“…ARPES measurements of graphene on Ir(111) clearly display a Dirac cone with the Dirac point shifted to 0.10 eV above E F [89]. However, the features of Dirac point were not observed in dI/dV spectra recorded on graphene on Ir(111) [112,113]. Decker et al investigated the structural and magnetic properties of cobalt-intercalated graphene on Ir(111) by using spin-polarized STM [114].…”