Electrical conduction properties of chemical vapor deposited graphene

• Main Authors: Yun-Lien Hsieh, 謝昀璉
• Other Authors: Watson Kuo
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/80574758566779667022

碩士 === 國立中興大學 === 物理學系所 === 101 === Graphene, an isolated single atomic layer of graphite, spotlights the practicability of the quantum confined systems. Here we report the optical and electric properties of graphene synthesized by chemical vapor deposition(CVD) on copper foils. The copper foil is etched by 0.25M ferric nitrate solution or 0.1M ammonium persulfate(APS) solution from backside. The graphene is transferred (assisted by PMMA)onto Si3N4/Si and SiO2/Si substrates, respectively. The Si3N4/Si substrates with Si3N4 membrane which thickness of 30nm, 75nm and 100nm . Through Raman spectrum mapping (with 488nm excitation laser), carbon signals are revealed an enhancement larger than 50% in D-band (1360cm-1) , G-band(1580cm-1) and 2D-band (2700cm-1) when the graphene was on sub-micrometer membranes. For studying their charge transport property, the grpaphene were transferred onto SiO2/Si substrates, followed by the fabrication of Al top gates. By modulating the gate voltage, we observed an ambipolar field effect and determined the Dirac point. The hole and the electron mobility both are on the order of 102cm2/V‧s . With sufficient magnetic field modulated, we observe Anderson localization at several temperatures.