Making angle-resolved photoemission measurements on corrugated monolayer crystals: Suspended exfoliated single-crystal graphene
Abstract
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 EF. Further, we show that suspended graphene behaves as a marginal Fermi liquid, with a quasiparticle lifetime that scales as (E-EF)-1; comparison with other graphene and graphite data is discussed.
- Publication:
-
Physical Review B
- Pub Date:
- September 2011
- DOI:
- 10.1103/PhysRevB.84.115401
- arXiv:
- arXiv:1104.2551
- Bibcode:
- 2011PhRvB..84k5401K
- Keywords:
-
- 73.22.Pr;
- 68.65.Pq;
- Condensed Matter - Materials Science
- E-Print:
- doi:10.1103/PhysRevB.84.115401