嵌入式纳米石墨烯碳膜中电子输运特性调控的原位电子显微研究

New developed graphene nanocrystallite embedded carbon (GNEC) film which having abundant directional graphene edges, has extraordinary magnetoelectric, piezoelectric and photoelectric properties, showing great application potential. However, the systematic understand on the mechanism of tailoring the GNEC film’s electric transport properties is still lacking, which is preventing the further improvement on its electric transport performance and practical application of relevant electric devices. Base on this background, we propose the scientific problem: “Tailoring the electric transport properties of graphene nanocrystallite embedded carbon film”. Through in-situ characterization and measurement with aberration corrected TEM and homemade four probe electric measurement platform, investigate the tailoring rule of GNEC film’s electric transport properties with controlled nanostructure. Then combining the atomic resolution STEM and differential phase contrast technique, monitoring the electric transport process inside the GNEC film’s atomic structure, study the electric transport mechanism inside the atomic structure of carbon film. In the end, investigate the effect of temperature and magnetic field strength and direction on the GNEC film’s electric transport. The research result will have great importance on systematically understanding the effect mechanism of GNEC film’s internal structure and external temperature and magnetic environment on its electric transport performance, effectively supporting the scientific design and fabrication of new generation carbon based electric devices.

新型的嵌入式纳米石墨烯碳膜由于含有丰富的定向纳米石墨烯边缘，拥有优异的磁电、压电、光电、催化等特性，显示了极好的应用前景。然而，目前对于其电子输运调控机理缺乏系统认识，阻碍了进一步优化性能推进相应电子器件实用化的步伐。基于上述背景，本项目提出“嵌入式纳米石墨烯碳膜中电子输运特性调控”这一科学问题。通过球差校正电镜和自制原位四探针电学测试平台进行原位观察测试，掌握碳膜内部结构对其整体电输运性能的调控规律。通过将扫描透射电子显微术与差分相衬成像术相结合，在原子尺度上观察碳膜内部结构的电子输运过程，深入研究碳膜原子、电子结构对其局域电输运性能的调控机制。最后通过调节外部温度以及磁场强度、方向，研究不同温度磁场环境对碳膜电子输运特性的影响规律与机制。研究结果对于系统认识不同温度磁场环境下嵌入式纳米石墨烯碳膜结构中的电输运特性本质有重要科学意义，为新型碳基电子器件的科学设计与制造提供支持。

针对“嵌入式纳米石墨烯碳膜中电子输运特性调控”这一科学问题，本项目开展了不同能量照射下辅助沉积的嵌入式纳米石墨烯碳膜的电学输运特性的原位透射电镜实验研究。通过搭建的四电极原位电学测试系统，对不同能量照射制备的碳膜的电导率、霍尔系数、载流子浓度以及霍尔迁移率进行了原位测量，并通过球差校正电镜原位观察了碳膜的原子电子结构，明确了碳膜内部石墨烯纳晶的尺寸与内部孔洞对碳膜电学输运性能的调控规律。通过对样品进行原位加热，以及改变电镜内部磁场强度与方向，观察了外部温度磁场环境对于碳膜电输运性能的微小影响，证实了碳膜电学性能较高的环境稳定性。发展了利用光子照射实现对碳膜结构进行调控的制备方法，为利用光子照射改变结构来调控嵌入式纳米石墨烯碳膜的电学输运性能奠定了基础。研究结果将建立纳米尺度下的嵌入式纳米石墨烯碳膜电学输运特性调控体系，为新型碳基电子期间的设计与制造提供支持。