title: Synthesis, characterization, electronic and gas-sensing properties towards H2 and CO of transparent, large-area, low-layer graphene.
abstract: Low-layered, transparent graphene is accessible by a chemical vapor deposition (CVD) technique on a Ni-catalyst layer, which is deposited on a <100> silicon substrate. The number of graphene layers on the substrate is controlled by the grain boundaries in the Ni-catalyst layer and can be studied by micro Raman analysis. Electrical studies showed a sheet resistance (R(sheet)) of approximately 1435 Ω per □, a contact resistance (R(c)) of about 127 Ω, and a specific contact resistance (R(sc)) of approximately 2.8×10(-4)  Ω cm(2) for the CVD graphene samples. Transistor output characteristics for the graphene sample demonstrated linear current/voltage behavior. A current versus voltage (I(ds)-V(ds)) plot clearly indicates a p-conducting characteristic of the synthesized graphene. Gas-sensor measurements revealed a high sensor activity of the low-layer graphene material towards H(2) and CO. At 300 °C, a sensor response of approximately 29 towards low H(2) concentrations (1 vol %) was observed, which is by a factor of four higher than recently reported.
authors.affiliation: Technische Universität Darmstadt, Eduard-Zintl-Institut, Fachbereich Chemie, Fachgebiet Anorganische Chemie, Petersenstrasse 18, 64287 Darmstadt, Germany.
authors.forename: Emine
authors.initials: E
authors.lastname: Kayhan
authors.forename: Ravi Mohan
authors.initials: RM
authors.lastname: Prasad
authors.forename: Alexander
authors.initials: A
authors.lastname: Gurlo
authors.forename: Oktay
authors.initials: O
authors.lastname: Yilmazoglu
authors.forename: Jörg
authors.initials: J
authors.lastname: Engstler
authors.forename: Emanuel
authors.initials: E
authors.lastname: Ionescu
authors.forename: Songhak
authors.initials: S
authors.lastname: Yoon
authors.forename: Anke
authors.initials: A
authors.lastname: Weidenkaff
authors.forename: Jörg J
authors.initials: JJ
authors.lastname: Schneider