Making angle-resolved photoemission measurements on corrugated monolayer crystals: Suspended exfoliated single-crystal graphene

Article

关键词: ELECTRONIC-STRUCTURE;    DIRAC FERMIONS;    GRAPHITE;    SPECTROSCOPY;    MICROSCOPY;    SURFACES;    DIFFRACTION;    SCATTERING;    DYNAMICS;    DISORDER;   

DOI  :  10.1103/PhysRevB.84.115401

来源: SCIE

【 摘 要 】

Free-standing exfoliated monolayer graphene is an ultrathin flexible membrane, which exhibits out-of-plane deformation or corrugation. In this paper, a technique is described to measure the band structure of such free-standing graphene by angle-resolved photoemission. Our results show that photoelectron coherence is limited by the crystal corrugation. However, by combining surface morphology measurements of the graphene roughness with angle-resolved photoemission, energy-dependent quasiparticle lifetime and band-structure measurements can be extracted. Our measurements rely on our development of an analytical formulation for relating the crystal corrugation to the photoemission linewidth. Our angle-resolved photoemission spectroscopy measurements show that, despite significant deviation from planarity of the crystal, the electronic structure of exfoliated suspended graphene is nearly that of ideal, undoped graphene; we measure the Dirac point to be within 25 meV of E-F. Further, we show that suspended graphene behaves as a marginal Fermi liquid, with a quasiparticle lifetime that scales as (E - E-F)(-1); comparison with other graphene and graphite data is discussed.

【 授权许可】

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