▎ 摘 要
A systematic study of the Cu-catalyzed chemical vapor deposition of graphene under extremely low partial pressure is carried out. A carbon precursor supply of just P-CH4 similar to 0.009 mbar during the deposition favors the formation of large-area uniform monolayer graphene verified by Raman spectra. A diluted HNO3 solution is used to remove Cu before transferring graphene onto SiO2/Si substrates or carbon grids. The graphene can be made suspended over a similar to 12 mu m distance, indicating its good mechanical properties. Electron transport measurements show the graphene sheet resistance of similar to 0.6 k Omega/square at zero gate voltage. The mobilities of electrons and holes are similar to 1800 cm(2)/Vs at 4.2 K and similar to 1200 cm(2)/Vs at room temperature.