The role of interfaces in organic spin valves revealed through spectroscopic and transport measurements
The role of interfaces in organic spin valves revealed through spectroscopic and transport measurements
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DOI：
10.1002/pssb.201147157
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发表时间：
2012-01
期刊：
影响因子：
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通讯作者：
A. Drew;G. Szulczewski;L. Nuccio;W. Gillin
中科院分区：
文献类型：
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作者：
A. Drew;G. Szulczewski;L. Nuccio;W. Gillin
不同材料之间的界面对许多电子设备的性能至关重要。在有源传输通过有机半导体(OSC)层的电子设备中，存在用于供应和移除载流子的金属电极。在金属/分子和分子/金属界面，电接触通常不是欧姆接触。因此，在大多数金属-有机半导体-金属器件中，电荷注入主要是通过隧道穿越势垒来控制的。当金属电极是铁磁性的时，占据和未占据电子态的密度与自旋有关，这对电子转移表现出进一步的微妙。在这篇文章中，我们总结了一些重要的实验结果，这些结果促进了我们对铁磁性金属(FM)/OSC界面上自旋极化电子转移的理解。特别是，我们重点介绍了关键的光谱研究，这些研究揭示了OSCs和FM之间，特别是Alq3与Co和Fe表面之间的电子结构的本质。我们讨论了这些系统的能级图与在自旋阀装置上进行的输运测量之间的关系。
Interfaces between dissimilar materials are critical to the performance of many electronic devices. In electrical devices where the active transport is through an organic semiconductor (OSC) layer there are metallic electrodes to supply and remove the charge carriers. At metal/molecule and molecule/metal interfaces the electrical contact is usually not Ohmic. As a result, in most metal‐organic semiconductors–metal devices charge injection is mainly governed by tunneling across the barriers. When the metal electrodes are ferromagnetic the density of occupied and unoccupied electronic states is spin‐dependent, which presents further subtleties to the electron transfer. In this article we summarize some of the important experimental results that have advanced our understanding of spin‐polarized electron transfer across ferromagnetic metal (FM)/OSC interfaces. In particular, we highlight key spectroscopic studies that have revealed insights into the nature of the electronic structure between OSCs and FMs, in particular between Alq3 and Co and Fe surfaces. We discuss the relationship between energy level diagrams for these systems and transport measurements made on spin‐valve devices.