Nickel enhanced graphene growth directly on dielectric substrates by molecular beam epitaxy

作者：Wofford Joseph M; Speck Florian; Seyller Thomas; Lopes Joao Marcelo J; Riechert Henning

来源：Journal of Applied Physics, 2016, 120(4): 045309.

DOI：10.1063/1.4958862

The efficacy of Ni as a surfactant to improve the crystalline quality of graphene grown directly on dielectric Al2O3(0001) substrates by molecular beam epitaxy is examined. Simultaneously exposing the substrate to a Ni flux throughout C deposition at 950 degrees C led to improved charge carrier mobility and a Raman spectrum indicating less structural disorder in the resulting nanocrystalline graphene film. X-ray photoelectron spectroscopy confirmed that no residual Ni could be detected in the film and showed a decrease in the intensity of the defect-related component of the C1s level. Similar improvements were not observed when a lower substrate temperature (850 degrees C) was used. A close examination of the Raman spectra suggests that Ni reduces the concentration of lattice vacancies in the film, possibly by catalytically assisting adatom incorporation. Published by AIP Publishing.

• 出版日期2016-7-28