Development of high spin-polarization spintronic devices based on organic molecular semiconductors

自旋电子学将电子的自旋和电荷特性应用于信息存储和处理，作为基于互补金属氧化物半导体（CMOS）的电子技术的一种有前途的替代品，它在过去几十年里对我们生活的几乎各个方面都产生了巨大的影响，正受到学术界和工业界的极大关注。特别是，有机电子学的最新进展不仅开辟了节能、机械柔性和大面积电子学的道路，而且由于分子半导体可以长时间和远距离保存自旋基信息，因此对自旋电子学应用非常有吸引力。然而，尽管全世界在有机自旋电子学领域进行了大量的研究，但在类晶体管结构中高效的自旋注入/输运仍然是包括有机自旋阀和自旋场效应晶体管（自旋场效应晶体管）在内的实用自旋电子器件发展中的一个长期挑战。这与磁性材料与有机半导体之间的界面问题密切相关，如大的导通失配、强的自旋表面偶极子相互作用以及结构缺陷，这些问题阻碍了自旋载流子有效注入有机半导体层。为了克服这些问题，实现实用的自旋电子器件，设计新的结构，最大限度地提高自旋转移过程的效率，并使用适当的表征工具来研究它们的磁/电子性质是至关重要的。本研究旨在揭示自旋电子器件中自旋注入和输运的详细机制，并开发可在磁场和电场中操作的磁性强的有机自旋阀和自旋场效应管。

Spintronics, where both spin and charge properties of electrons are applied to information storage and processing, is garnering tremendous attention from academia and industry as a promising alternative to the complementary metal-oxide-semiconductor (CMOS)-based electronics technology which has impacted immensely on our lives in nearly all aspects for past decades. Especially, recent progress in organic electronics has not only opened the way to the energy-efficient, mechanically flexible, and large-area electronics, but also made molecular semiconductors very attractive for spintronics applications since they can preserve the spin-based information over long time and distance. However, despite intensive research efforts in the field of organic spintronics worldwide, highly efficient spin-injection/transport in transistor-like structures still remains a long-standing challenge in the development of practical spintronic devices including organic spin-valves and spin field-effect transistors (spin-FETs). This is strongly correlated with the interface problems between magnetic materials and organic semiconductors, such as large conduction mismatch, strong spin-surface dipole interaction, and structural defects, which prevent efficient injection of spin carriers into organic semiconductor layer. To overcome these problems and realize practical spintronic devices, it is crucial to devise new architectures, which maximize the efficiency of spin-transfer process, and to investigate their magnetic/electronic properties using the adequate characterization tools. The proposed research aims to shed light on the detailed mechanism of spin-injection and transport in spintronic devices and to develop magnetically robust organic spin-valves and spin-FETs operatable in both magnetic and electric fields.