Development of inorganic/organic-based diluted magnetic semiconductors for spin-polarized transistors

毫无疑问，在过去的30年里，半导体电子技术的进步对我们的生活水平产生了巨大的影响。这种快速增长是由各种电子设备的规模化驱动的。然而，最近预测，传统半导体电子器件在不久的将来将面临根本性的限制。当器件尺寸缩小到低于约10 nm（目前为65 nm）时，由于电子的量子行为，已知不可能进行可靠的信息处理。为了克服这个问题并取得进一步的进展，利用自旋相关和电荷相关电流的自旋电子学（或自旋电子学）已被广泛开发，作为仅依赖于电流的二进制状态（1或0位）的半导体技术的有前途的替代方案。我提出这个研究计划是为了生产新的铁磁半导体，这是自旋电子学的关键元素。自旋是电子的固有属性，可以表现为两种可区分的磁能状态（上自旋和下自旋）。传统的基于半导体的电子器件仅利用电荷自由度（正空穴和负电子）而不考虑电荷载流子的自旋性质，因为在当前可用的半导体材料中不存在铁磁性。因此，自旋电子学技术需要新的半导体，其显示铁磁行为，从而允许产生和控制自旋极化电子的电流，并在现有半导体结构中长时间和长距离地保持自旋相干性。将磁性结合到有机和无机基半导体材料将尝试使用磁性杂质掺杂方法。铁磁半导体及其传输自旋极化电子的能力将促进未来自旋电子器件的实现，包括自旋晶体管，磁存储器，在磁场和电场中工作的逻辑电路。

There is no doubt that progress in the semiconductor electronics has impacted immensely on our standard of living in the past 30 years. This rapid growth has been driven by scaling a variety of electronic devices. However, it was recently predicted that traditional semiconductor electronics will face fundamental limitations in near future. When the device scaling goes below around 10 nm (65 nm at present), a reliable information processing is known to be impossible due to the quantum behavior of electrons. To overcome this problem and attain further progress, spin-electronics (or spintronics) utilizing both spin-dependent and charge-dependent electric currents has been intensively exploited as a promising alternative to the semiconductor technology relying only on the binary states of electric current (bit of 1 or 0). I am proposing this research program to produce new ferromagnetic semiconductors which is a key element in spin-electronics. The spin is an intrinsic property of electrons which can be manifested as two distinguishable magnetic-energy states (spin-up and spin-down). The conventional semiconductor-based electronics have utilized only the charge degree of freedom (positive holes and negative electrons) without considering the spin properties of charge carriers because ferromagnetism is absent in currently available semiconducting materials. Therefore spintronics technology requires new semiconductors which show ferromagnetic behavior and thus allow a current of spin-polarized electrons to be generated and controlled, and preserve the spin-coherence over long time and distance in an existing semiconductor structure. The incorporation of magnetism into organic-and inorganic-based semiconducting materials will be attempted using the magnetic-impurity doping method. This work on ferromagnetic semiconductors and their abilities to transport the spin-polarized electrons will facilitate the realization of future spintronic devices, including spin-transistors, magnetic memory, logic-circuits working both in magnetic and electric fields.