摘要
以化学气相沉积(CVD)制备的单层石墨烯为原料,小分子三嗪为掺杂剂,采用吸附掺杂的方式,在低温下对石墨烯实现n型掺杂。利用拉曼光谱(Raman)、X射线光电子能谱分析(XPS)、原子力显微镜(AFM)、紫外分光光度计(UV)和霍尔效应测试仪(Hall)对样品的形貌、结构及电学性能进行表征。结果表明:该方法简单安全,能够对石墨烯实现均匀的n型掺杂,掺杂石墨烯的透光率达到95%。掺杂后石墨烯的特征峰G峰和2D峰向高波数移动。掺杂180 min后,载流子浓度达到4×10~(12)/cm~2,接近掺杂前的载流子浓度,掺杂后的石墨烯在450℃的退火温度下具有可逆能力,其表面电阻在300℃以下具有较好的稳定性。
Nitrogen-doped graphene(N-graphene) was prepared via molecular doping from sym Triazine molecules at low temperature. The phase structure, morphology and electrical property were characterized by Raman spectroscopy(Raman), X-ray photoelectron spectroscope(XPS), atomic force microscope(AFM), ultraviolet spectrophotometer(UV), and Hall tester. Here the method provides a simple and safe process to grow N-graphene. The morphology of N-graphene retains good uniformity, and the transmittance of the graphene is 95% in the range from 300 nm to 800 nm. The typical graphene peaks G-band and 2D-band both upshift after doping. The hole-carrier concentration is decreased immediately after Triazine decoration. After exposure to Triazine for 3 h, the charge-carrier concentration of N-graphene remains as high as 4×10~(12)/cm~2, which approaching the pristine Chemical Vapor Deposition(CVD) graphene's carrier concentration due to the abundant molecular doping. After N-graphene annealed at 450℃, a hole-carrier concentration of ~8×1012/cm2 can be regenerated. The sheet resistance of N-graphene can stay steady at 300℃. The mechanism of Triazine doping is that Triazine is an electron-rich aromatic molecule due to the incorporation of N atoms in the aromatic ring, and some negative charges are expected to transfer onto the graphene. This research provides a simple method to obtain N-graphene doping for future application in electrical devices.
引文
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