High thermal stability quasi-free-standing bilayer graphene formed on 4H-SiC(0001) via platinum intercalation

Influences on electronic structure induced by platinum (Pt) deposited on monolayer graphene grown on SiC(0001) are investigated by photoelectron spectroscopy (PES), selected area low energy electron diffraction (mu-LEED) and angle resolved photoelectron spectroscopy (ARPES) techniques at the MAX Laboratory. Stable monolayer graphene electronic properties are observed after Pt deposition and after annealing at temperatures below 600 degrees C. At >= 600 degrees C platinum silicide forms at the graphene/SiC interface. Annealing at 900 degrees C results in an efficient decoupling of the carbon buffer layer from the SiC substrate and transformation into a second graphene layer. At this stage a quasi-free standing bi-layer graphene sample is obtained. The new superstructure spots then appearing in mu-LEED pattern suggest formation of an ordered platinum silicide at the interface. This silicide is found to be stable even after annealing at temperature up to 1200 degrees C. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).