综合利用电子的电荷和自旋两种属性而发展的半导体自旋器件因具有信息存储的非挥发性等优点是最具前景的下一代电子器件之一。半导体Ge因具有高电子迁移率是下一代MOSFET的沟道材料之一，故Ge自旋器件备受关注。但目前向Ge沟道的自旋注入效率低、结电阻面积乘积高、自旋电子在Ge中的输运性质及影响Hanle曲线幅值的物理机制不清楚，使Ge自旋器件发展较为缓慢。针对此问题，本项目首先构筑新的Co2MnSi/石墨烯/Ge异质结，将其制备成三端子和非局域四端子电极配置的器件结构，拟实现向Ge沟道高效低阻自旋注入。其次，测定Hanle和自旋阀效应的温度和偏压依存性，拟揭示自旋电子在Ge沟道中的输运性质。最后，综合采用三端子电极配置的自旋电子注入方法和x-射线光电子能谱技术从电学和能带结构两方面研究影响Hanle曲线幅值的物理机制。以上研究成果可为Ge自旋电子器件开辟新途径，具有重要理论意义和应用前景。

Semiconductor-based spintronic device in which both the charge and spin of the electron are utilized to provide new functionalities such as nonvolatility，is one of the candidates for next generation electronic devices. A semiconducting germanium channel with high electron mobility is one candidate of the next generation MOSFETs, and thus studies on spintronic devices with a germanium channel have attracted increasing attention in recent years. However, the evolvement of the germanium spintronic device is seriously delayed at present due to the low spin injection efficiency, high resistance-area product, the unclear transport properties of electrons in germanium channel and the unknown physical mechanism of the anomalous scaling of Hanle effect curves. To solve the above-mentioned issues, we proposed a new research program here. Firstly, we will prepare a new heterostructure consisting of Co2MnSi/graphene/Ge, which will be further fabricated with three-terminal and four-terminal configurations to achieve an efficient and low-resistance spin injection into germanium. Secondly, the spin transport properties of the electrons in germanium channel will be disclosed by the measurement of a temperature and a bias voltage dependence of Hanle and spin valve effect. Finally, the spin injection method with three-terminal configuration and the x-ray photoelectron spectroscopy technology will be comprehensive utilized to analyze the physical mechanism of Hanle effect from electrics and energy band structures. The findings may open up a new way for future germanium-based spintronic devices and have great theoretical significance and valuable potential applications.