title: Bi- and trilayer graphene solutions.
abstract: Bilayer and trilayer graphene with controlled stacking is emerging as one of the most promising candidates for post-silicon nanoelectronics. However, it is not yet possible to produce large quantities of bilayer or trilayer graphene with controlled stacking, as is required for many applications. Here, we demonstrate a solution-phase technique for the production of large-area, bilayer or trilayer graphene from graphite, with controlled stacking. The ionic compounds iodine chloride (ICl) or iodine bromide (IBr) intercalate the graphite starting material at every second or third layer, creating second- or third-stage controlled graphite intercolation compounds, respectively. The resulting solution dispersions are specifically enriched with bilayer or trilayer graphene, respectively. Because the process requires only mild sonication, it produces graphene flakes with areas as large as 50 µm(2). Moreover, the electronic properties of the flakes are superior to those achieved with other solution-based methods; for example, unannealed samples have resistivities as low as ∼1 kΩ and hole mobilities as high as ∼400 cm(2) V(-1) s(-1). The solution-based process is expected to allow high-throughput production, functionalization, and the transfer of samples to arbitrary substrates.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Chih-Jen
authors.initials: CJ
authors.lastname: Shih
authors.forename: Aravind
authors.initials: A
authors.lastname: Vijayaraghavan
authors.forename: Rajasekar
authors.initials: R
authors.lastname: Krishnan
authors.forename: Richa
authors.initials: R
authors.lastname: Sharma
authors.forename: Jae-Hee
authors.initials: JH
authors.lastname: Han
authors.forename: Moon-Ho
authors.initials: MH
authors.lastname: Ham
authors.forename: Zhong
authors.initials: Z
authors.lastname: Jin
authors.forename: Shangchao
authors.initials: S
authors.lastname: Lin
authors.forename: Geraldine L C
authors.initials: GL
authors.lastname: Paulus
authors.forename: Nigel Forest
authors.initials: NF
authors.lastname: Reuel
authors.forename: Qing Hua
authors.initials: QH
authors.lastname: Wang
authors.forename: Daniel
authors.initials: D
authors.lastname: Blankschtein
authors.forename: Michael S
authors.initials: MS
authors.lastname: Strano