高质量大面积石墨烯的化学气相沉积制备方法研究

Research on synthesis of high-quality and large-scale graphene films by chemical vapor deposition

石墨烯因其奇特的能带结构和优异的物理性能而成为近年来研究的热点,但是目前单层石墨烯的质量与尺寸制约了其实际应用的发展.本文采用常压化学气相沉积(CVD)方法,基于铜箔衬底,利用甲烷作为碳源制备了高质量大面积的单层与多层石墨烯.研究发现:高温度、稀薄的甲烷浓度、较短的生长时间以及合适的气体流速是制备高质量、大面积石墨烯的关键.Raman光谱、扫描电子显微镜、透射电子显微镜等表征结果表明:制备的石墨烯主要为单层,仅铜箔晶界处有少量多层石墨烯.电学测试表明CVD制备的石墨烯在低温时呈现出较明显的类半导体特性;薄膜电阻随外界磁场的增大而减小.

Graphene has aroused great interest because of its peculiar band structure and excellent physical properties.But today,the development of graphene is limited to its size and quality.In this paper,single- and multilayer graphene films are synthesized on copper foils by chemical vapor deposition（CVD） using methane at ambient pressure.Experimental results find that the high temperature,low concentration of methane gas,shorter growth time and suitable gas flow are the key to obtaing the high-quality and large-scale graphene films.Raman spectra,scanning electron microscope and transmission electron microscope characterization indicate the graphene films are mostly of single-layer structure,only a few of multilayer graphene films are observed around the copper boundaries.Further electrical tests show that the graphene films grown by CVD method represent semiconductor behavior under low temperature and the sheet resistances of graphene films decrease with the external magnetic field increasing.