Department of Applied Physics, Center for NanoMaterials, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands.
Nat Commun. 2013;4:2286. doi: 10.1038/ncomms3286.
Harnessing the spin degree of freedom in semiconductors is generally a challenging, yet rewarding task. In recent years, the large effect of a small magnetic field on the current in organic semiconductors has puzzled the young field of organic spintronics. Although the microscopic interaction mechanisms between spin-carrying particles in organic materials are well understood nowadays, there is no consensus as to which pairs of spin-carrying particles are actually influencing the current in such a drastic manner. Here we demonstrate that the spin-based particle reactions can be tuned in a blend of organic materials, and microscopic mechanisms are identified using magnetoresistance lineshapes and voltage dependencies as fingerprints. We find that different mechanisms can dominate, depending on the exact materials choice, morphology and operating conditions. Our improved understanding will contribute to the future control of magnetic field effects in organic semiconductors.
在半导体中利用自旋自由度通常是一项具有挑战性但又有回报的任务。近年来，磁场对有机半导体中电流的微小影响令有机自旋电子学这一新兴领域感到困惑。尽管如今人们已经很好地理解了有机材料中载流子自旋之间的微观相互作用机制，但对于哪些载流子自旋对电流产生如此剧烈的影响，尚无共识。在这里，我们证明了自旋基粒子反应可以在有机材料混合物中进行调节，并使用磁阻线形状和电压依赖性作为指纹来识别微观机制。我们发现，不同的机制可能会根据具体的材料选择、形态和操作条件而占主导地位。我们对这一现象的深入理解将有助于未来控制有机半导体中的磁场效应。
