Synthesis of isotopically-labeled graphite films by cold-wall chemical vapor deposition and electronic properties of graphene obtained from such films
Chemical vapor deposition (CVD), isotopically-labeled graphite, graphene
We report the synthesis of isotopically-labeled graphite fi lms on nickel substrates by using cold-wall chemical vapor deposition (CVD). During the synthesis, carbon from 12C- and 13C-methane was deposited on, and dissolved in, a nickel foil at high temperature, and a uniform graphite film was segregated from the nickel surface by cooling the sample to room temperature. Scanning and transmission electron microscopy, micro- Raman spectroscopy, and X-ray diffraction prove the presence of a graphite fi lm. Monolayer graphene fi lms obtained from such isotopically-labeled graphite fi lms by mechanical methods have electron mobility values greater than 5000 cm2·V 1·s 1 at low temperatures. Furthermore, such films exhibit the half-integer quantum Hall effect over a wide temperature range from 2 K to 200 K, implying that the graphite grown by this cold-wall CVD approach has a quality as high as highly oriented pyrolytic graphite (HOPG). The results from transport measurements indicate that 13C-labeling does not significantly affect the electrical transport properties of graphene.
Tsinghua University Press
Weiwei Cai,Richard D. Piner,Yanwu Zhu,Xuesong Li,Zhenbing Tan,Herman Carlo Floresca,Changli Yang,Li Lu,M. J. Kim,Rodney S. Ruoff, Synthesis of isotopically-labeled graphite films by cold-wall chemical vapor deposition and electronic properties of graphene obtained from such films. NanoRes.2009, 2: 851-856