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Synthesis, Characterization, Electronic and Gas‐Sensing Properties towards H 2 and CO of Transparent, Large‐Area, Low‐Layer Graphene
Author(s) -
Kayhan Emine,
Prasad Ravi Mohan,
Gurlo Alexander,
Yilmazoglu Oktay,
Engstler Jörg,
Ionescu Emanuel,
Yoon Songhak,
Weidenkaff Anke,
Schneider Jörg J.
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201201880
Subject(s) - graphene , materials science , raman spectroscopy , chemical vapor deposition , substrate (aquarium) , contact resistance , layer (electronics) , sheet resistance , silicon , nanotechnology , optoelectronics , analytical chemistry (journal) , chemistry , optics , oceanography , physics , geology , chromatography
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.