Graphene on Ir(111) characterized by angle-resolved photoemission

Abstract

Angle resolved photoelectron spectroscopy (ARPES) is extensively used to characterize the dependence of the electronic structure of graphene on Ir(111) on the preparation process. ARPES findings reveal that temperature programmed growth alone or in combination with chemical vapor deposition leads to graphene displaying sharp electronic bands. The photoemission intensity of the Dirac cone is monitored as a function of the increasing graphene area. Electronic features of the moir\'e superstructure present in the system, namely minigaps and replica bands are examined and used as robust features to evaluate graphene uniformity. The overall dispersion of the pi-band is analyzed. Finally, by the variation of photon energy, relative changes of the pi- and sigma-band intensities are demonstrated.Comment: 8 pages, 6 figures in published for

Finding the bare band: Electron coupling to two phonon modes in potassium-doped graphene on Ir(111)

“…5 Note that the full width at half maximum of the MDC at an energy just below the Fermi level (Fig. 2) is 0.022 Å -1 , which is even slightly smaller than the width measured for bare graphene on Ir(111) 23 and comparable to non-intercalated graphene on SiC 5 . The measured width of 0.022 Å -1 is substantially smaller than the previously reported value of 0.095 Å -1 for the same system.…”

“…23,32 Potassium was added at room temperature by evaporation from a getter source, until a clear 2×2 structure emerged in LEED and no additional doping of graphene bands could be achieved.…”

“…15 An ARPES study on another metallic system -graphene on a copper foil -questions all previous findings, proposing an order of magnitude smaller electron-phonon coupling strength. 17 In this paper we present results of an ARPES study of highly ordered graphene on Ir(111) 23,24 intercalated 25 with potassium. We use maxima of momentum distribution curves (MDC) and energy distribution curves (EDC) to determine the exact dispersion of the π * band along the K-M direction.…”

Hole doping of graphene supported on Ir(111) by AlBr3

“…Another manifestation of this interaction is the faded replica π bands at around ± 0.3Å −1 from theK point and the minigaps at around 0.75 eV on the main π band (discussed in detail in Ref. [40][41][42], which are clearly visible in Fig. 3(b).…”

Variation of the character of spin-orbit interaction by Pt intercalation underneath graphene on Ir(111)

“…Graphene on Ir(111) is a well-studied system with a weak interaction with the substrate [22][23][24][25][26]. It is characterized by the 9.3 × 9.3 moiré superstructure, and geometrical corrugation which arises from the lattice mismatch of graphene with respect to the Ir(111).…”