Effect of functionalization on the electrostatic charging, tunneling, and Raman spectroscopy of epitaxial graphene

Jeongmin Hong (1, 2) , Sandip Niyogi (3) , Elena Bekyarova (3) , Mikhail E. Itkis (3) , Palanisamy Ramesh (3) , Claire Berger (4) , Walt A. de Heer (4) , Robert C. Haddon (3) , Sakhrat Khizroev (1, 2)

1 Department of Electrical and Computer Engineering
2 Department of Electrical Engineering [Riverside]
3 Center for Nanoscale Science and Engineering [Riverside]
4 School of Physics

The authors report the effects of radical functionalization on the electrostatic force microscopy (EFM), the scanning tunneling spectra (STS), and Raman spectroscopy of epitaxial graphene. The EFM studies show the existence of layer dependent trapped charges in the pristine graphene. The uniform enhancement of energy gap is observed through STS. Raman spectra show nonuniformly distributed D-band intensities throughout the functionalized sample as a result of the inhomogeneous distribution of covalent bonds to the graphene sheets. The functionalization chemistry has a marked effect on the homogeneity of the electrostatic charge and leads to an increase of the energy of the band gap.

Domains: Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]

Jeongmin Hong, Sandip Niyogi, Elena Bekyarova, Mikhail E. Itkis, Palanisamy Ramesh, et al.. Effect of functionalization on the electrostatic charging, tunneling, and Raman spectroscopy of epitaxial graphene. Journal of Vacuum Science & Technology B Microelectronics and Nanometer Structures, 2012, 30, pp.03D103. ⟨10.1116/1.3693417⟩. ⟨hal-01002905⟩