title: Raman spectrum of graphene and graphene layers.
abstract: Graphene is the two-dimensional building block for carbon allotropes of every other dimensionality. We show that its electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers. The D peak second order changes in shape, width, and position for an increasing number of layers, reflecting the change in the electron bands via a double resonant Raman process. The G peak slightly down-shifts. This allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area.
authors.affiliation: Cambridge University, Engineering Department, JJ Thompson Avenue, Cambridge CB3 0FA, United Kingdom. acf26@eng.cam.ac.uk
authors.forename: A C
authors.initials: AC
authors.lastname: Ferrari
authors.forename: J C
authors.initials: JC
authors.lastname: Meyer
authors.forename: V
authors.initials: V
authors.lastname: Scardaci
authors.forename: C
authors.initials: C
authors.lastname: Casiraghi
authors.forename: M
authors.initials: M
authors.lastname: Lazzeri
authors.forename: F
authors.initials: F
authors.lastname: Mauri
authors.forename: S
authors.initials: S
authors.lastname: Piscanec
authors.forename: D
authors.initials: D
authors.lastname: Jiang
authors.forename: K S
authors.initials: KS
authors.lastname: Novoselov
authors.forename: S
authors.initials: S
authors.lastname: Roth
authors.forename: A K
authors.initials: AK
authors.lastname: Geim