Room-temperature spintronic effects in Alq3-based hybrid devices
Room-temperature spintronic effects in Alq3-based hybrid devices
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DOI：
10.1103/physrevb.78.115203
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发表时间：
2008-09-01
影响因子：
3.7
通讯作者：
Zhan, Y.
中科院分区：
文献类型：
--
作者：
Dediu, V.;Hueso, L. E.;Zhan, Y.
报道了Alq（3）有机半导体长（102 nm）沟道中自旋极化的高效注入和输运。我们采用垂直自旋阀器件与底部锰氧化物电极和Alq 3之间的直接界面，而顶部电极的几何形状由放置在“软”有机半导体和顶部Co电极之间的绝缘隧道势垒组成。该解决方案减少了由金属渗透引起的所谓的不明确层的普遍存在的问题，所述不明确层延伸到有机层中高达约50-100 nm的距离并且阻止实现具有明确限定的几何形状的器件。对于我们的器件，厚度被定义为具有约2.5nm的精度，这接近Alq 3分子尺寸。我们证明了有效的自旋注入在两个接口的设备与100纳米和200纳米厚的通道。我们解决了有机自旋电子学中最有争议的问题之一：Alq（3）基器件中自旋输运的温度限制。我们通过改善铁磁/Alq（3）界面的自旋注入特性来实现室温自旋阀操作来澄清这个问题。此外，我们讨论了性质的反符号的自旋阀效应在这样的设备提出了一种机制，自旋运输。
We report on efficient spin polarized injection and transport in long (102 nm) channels of Alq(3) organic semiconductor. We employ vertical spin valve devices with a direct interface between the bottom manganite electrode and Alq3, while the top-electrode geometry consists of an insulating tunnel barrier placed between the " soft" organic semiconductor and the top Co electrode. This solution reduces the ubiquitous problem of the so-called ill-defined layer caused by metal penetration, which extends into the organic layer up to distances of about 50-100 nm and prevents the realization of devices with well-defined geometry. For our devices the thickness is defined with an accuracy of about 2.5 nm, which is near the Alq3 molecular size. We demonstrate efficient spin injection at both interfaces in devices with 100- and 200-nm-thick channels. We solve one of the most controversial problems of organic spintronics: the temperature limitations for spin transport in Alq(3)-based devices. We clarify this issue by achieving room-temperature spin valve operation through the improvement of spin injection properties of both ferromagnetic/Alq(3) interfaces. In addition, we discuss the nature of the inverse sign of the spin valve effect in such devices proposing a mechanism for spin transport.