Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Chemin du Musée 3, CH-1700 Fribourg, Switzerland.
Nat Mater. 2011 Jan;10(1):39-44. doi: 10.1038/nmat2912. Epub 2010 Dec 5.
Spintronics has shown a remarkable and rapid development, for example from the initial discovery of giant magnetoresistance in spin valves to their ubiquity in hard-disk read heads in a relatively short time. However, the ability to fully harness electron spin as another degree of freedom in semiconductor devices has been slower to take off. One future avenue that may expand the spintronic technology base is to take advantage of the flexibility intrinsic to organic semiconductors (OSCs), where it is possible to engineer and control their electronic properties and tailor them to obtain new device concepts. Here we show that we can control the spin polarization of extracted charge carriers from an OSC by the inclusion of a thin interfacial layer of polar material. The electric dipole moment brought about by this layer shifts the OSC highest occupied molecular orbital with respect to the Fermi energy of the ferromagnetic contact. This approach allows us full control of the spin band appropriate for charge-carrier extraction, opening up new spintronic device concepts for future exploitation.
自旋电子学发展迅速，例如，从最初在自旋阀中发现巨磁电阻到在硬盘读取头中广泛应用，这在相对较短的时间内就实现了。然而，将电子自旋作为半导体器件中的另一个自由度充分利用的能力发展则较为缓慢。未来可能会拓展自旋电子技术基础的一个途径是利用有机半导体（OSC）固有的灵活性，通过设计和控制其电子特性并对其进行调整以获得新的器件概念。在这里，我们展示了通过包含薄的界面层的极性材料，我们可以控制从 OSC 中提取的电荷载流子的自旋极化。该层引起的电偶极矩会使 OSC 的最高占据分子轨道相对于铁磁接触的费米能发生移动。这种方法使我们可以完全控制适合电荷载流子提取的自旋能带，为未来的开发开辟了新的自旋电子器件概念。
