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

毫无疑问，过去 30 年半导体电子技术的进步对我们的生活水平产生了巨大影响。这种快速增长是由各种电子设备的扩展推动的。然而，最近有人预测，传统的半导体电子产品在不久的将来将面临根本性的限制。当器件尺寸低于 10 nm（目前为 65 nm）时，由于电子的量子行为，可靠的信息处理是不可能的。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，作为仅依赖于电流二元态（1或0位）的半导体技术的有前途的替代方案。我提议这个研究计划是为了生产新型铁磁半导体，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（自旋向上和自旋向下）。传统的基于半导体的电子器件仅利用电荷自由度（空穴和负电子），而没有考虑电荷载流子的自旋特性，因为当前可用的半导体材料不存在铁磁性。因此，自旋电子学技术需要具有铁磁行为的新型半导体，从而允许产生和控制自旋极化电子电流，并在现有半导体结构中长时间和距离保持自旋相干性。将尝试使用磁性杂质掺杂方法将磁性融入有机和无机半导体材料中。这项关于铁磁半导体及其传输自旋极化电子的能力的工作将有助于实现未来的自旋电子器件，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.