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）的电子技术的有前途的替代品，自旋电子学正在学术界和工业界获得巨大的关注，CMOS电子技术在过去几十年中几乎在各个方面对我们的生活产生了巨大的影响。特别是近年来有机电子学的发展，不仅为高能效、机械柔性和大面积电子学开辟了道路，而且由于分子半导体可以长时间和长距离地保存自旋信息，因此在自旋电子学应用中也具有很大的吸引力。然而，尽管全世界在有机自旋电子学领域进行了深入的研究，但在包括有机自旋阀和自旋场效应晶体管（spin-FET）的实际自旋电子器件的开发中，晶体管类结构中的高效自旋注入/输运仍然是一个长期存在的挑战。这与磁性材料和有机半导体之间的界面问题密切相关，例如大的传导失配、强的自旋-表面偶极相互作用和结构缺陷，这些问题阻止自旋载流子有效地注入到有机半导体层中。为了克服这些问题，实现实用的自旋电子器件，这是至关重要的，设计新的架构，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/电特性。该研究旨在阐明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稳健的有机自旋阀和自旋FET。

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.