有机自旋电子器件中有机材料结构和界面结构的调控

Spintronics is a promising and exciting field which enables the achievement of high-performance and low power-consuming electronic devices combining the memory and logic operation. Pi-conjugated molecular and polymeric materials, which exhibit exceptionally low degree of spin scattering, are the excellent candidates as the medium of spin transport. In this project, we will utilize the organic semiconductors with different molecular structures as the spacer in the organic spin valves (SV). By establishing the well-defined conditions of film preparation, the comprehensive investigation will be performed on the role of structural ordering and the defect states of the organic spacers as well as the structural factors of the organic/magnetic electrode interface on spin injection and transport as well as the magnetoresistance (MR) of the organic SVs. The study will also be performed to unveil the interplays between the structure (and trap states) of organic spacers, the mechanism of carrier transport and the mechanism controlling spin transport. It is to explore new physics and shed a new light on some of puzzles related to the structural aspects in organic spintronics. In addition, we will actively engineer the structure of the organic spacers and the organic/electrode interfaces by the novel methods. The efforts will be made to search the effective approaches 1)to manipulate the efficiency and process of the spin injection and transport; 2) to achieve high MR of the organic spin valves and 3) to improve the device reproducibility. The research proposed in the project will be of high significance to get a deeper insight on the mechanism of spin injection and transport in organic semiconductors as well as to develop the novel high-performance spintronic device

自旋电子学的研究将可能实现高性能低能耗的电子信息器件，因而是当前的研究热点。Pi-共轭分子和聚合物材料具有非常弱的自旋散射作用，是自旋极化传输的理想候选材料。本项目拟选择不同分子结构的有机半导体作为自旋极化传输介质。通过控制制备条件，研究其薄膜结构有序度和缺陷态等因素以及有机/磁电极界面结构对自旋注入/传输特性和磁电阻器件性能的影响；揭示有机半导体材料微结构与载流子传输机制和自旋输运过程这三者间的内在关系，探索其中的新现象和新规律,澄清仍困扰有机自旋电子学界的一些重要问题。并采用独特有效的方法对有机材料结构和有机-磁电极界面结构进行调控，来探索控制自旋极化注入和传输的效率，提高有机自旋电子器件性能(如磁电阻率)和器件可靠性的有效途径。本项目的研究将对深入理解有机半导体自旋极化注入/传输机制，发展高性能和新型自旋电子器件方面具有重要意义。

自旋电子学的研究可能实现高性能低能耗的电子信息器件，是当前的研究热点。Pi-共轭分子和聚合物材料具有非常弱的自旋散射作用，是自旋极化传输的理想候选材料。本项目选择几种重要的半导体聚合物和分子半导体作为自旋极化传输介质。通过控制生长条件和采用一些独特薄膜制备方法，实现了有机半导体薄膜结构的调控，深入研究了分子结构、分子聚集态、分子取向以及薄膜结构有序度和缺陷态等因素对自旋传输特性和磁电阻器件性能的影响。结合其电荷传输性能的研究，揭示出有机半导体材料微结构与载流子传输机制和自旋输运过程这三者间的内在关系，建立了初步的模型，并寻找出了若干具有优异的自旋传输性能的有机半导体新材料。此外还运用综合性的结构和电输运表征手段，深入研究了有机/磁电极界面的化学态和电子结构及其对电荷/自旋极化注入的影响。并采用有效的方法（如磁电极表面的石墨烯钝化）对有机-磁电极界面结构进行调控，实现自旋极化注入效率的控制和提高。通过本项目的研究,发现了一些重要的新现象新规律以及提高有机自旋电子器件性能(如磁电阻率)和器件可靠性的有效途径，对深入理解有机半导体的自旋极化注入/传输机制、发展高性能自旋电子器件具有重要意义。已发表SCI论文5篇，培养博士和硕士研究生共6名。