电弧放电法制备石墨烯及其在导电油墨中的应用

Graphene Nanosheets Prepared by Arc Discharge Method and Their Application in Conductive Inkjet

导电油墨是印刷电子技术中使用的关键电子材料,而导电填料作为导电油墨的主要成分要求其化学性能稳定且电导率高。其中,基于石墨烯的导电油墨因为其优异的电学性质受到广泛关注。本研究采用直流电弧放电法制备的石墨烯作为导电填料,并通过扫描电子显微镜、透射电子显微镜、拉曼光谱等手段对制备的石墨烯进行了表征。结果表明:直流电弧放电法制备的石墨烯为2~10层、尺寸在100~200 nm范围且纯度高、结晶性好。在此基础上,研究了涂层厚度、热处理温度以及弯曲角度等对石墨烯导电油墨导电性能的影响。研究发现,石墨烯导电油墨电阻率与涂层厚度、热处理温度成反比,且随着厚度、温度的增加石墨烯导电油墨的电阻率逐渐降低。并且样品在柔性基底上经过不同角度的弯曲折叠后电阻率没有明显变化。当厚度为170μm的样品经过360℃(30 min)热处理后,石墨烯导电油墨的电阻率仅为0.003?·cm。上述结果表明,电弧法制备的石墨烯导电油墨有望成为未来印制电子领域的关键材料。

Conductive ink is one of the dominant electronic materials for printed electronics technology. As the main component in conductive inks, conductive fillers are required to have favorable electronic properties and good chemical stability. Up to date, graphene-based conductive ink has attracted enormous research interest mainly due to its remarkable electrical properties. In present study, the graphene sheets as the conductive fillers were fabricated via a direct current arc discharge evaporation method. Furthermore, the as-prepared graphene sheets were characterized by scanning electron microscope （SEM）, transmission electron microscope （TEM） and Raman spectra analysis. The resuits demonstrated that the graphene sheets consisting of 2-10 layers with sheet size ranging from 100 nm to 200 nm had high purity and high crystallinity. Besides, the relationships between conductive properties and coating thicknesses, annealing temperatures and bending angles of conductive ink, were also carded out. It was found that the resistivity of conductive ink was inversely proportional to its thickness and annealing temperature, i.e. with gradual increase in thickness and temperature, the resistivity was decreased. And the resistivity of the conductive ink on the flexible sub-strate remained stable under different folding angles. Specially, the conductive ink with a thickness of 170 μm achieved the specific resistivity of 0.003 Ω·cm after being annealed at 360℃ for 30 min. The results indicate that arc-discharge graphene sheets are promising alternative for next generation of printed electronics.