Control of Schottky Barriers in Single Layer MoS2 Transistors with Ferromagnetic Contacts
Control of Schottky Barriers in Single Layer MoS2 Transistors with Ferromagnetic Contacts
复制标题
DOI：
10.1021/nl4010157
复制
发表时间：
2013-07-01
期刊：
影响因子：
10.8
通讯作者：
Kawakami, Roland K.
中科院分区：
文献类型：
--
作者：
Chen, Jen-Ru;Odenthal, Patrick M.;Kawakami, Roland K.
MoS_2及其相关的金属二卤化物(MoSe_2、WS_2、WSe_2)是一种层状的二维材料，在纳米电子学和自旋电子学领域具有广阔的应用前景。例如，在单层(SL)MoS2的价带中，大的自旋轨道耦合和自旋分裂可以导致自旋寿命的延长和大的自旋霍尔角。了解接触的性质是在MoS2中实现自旋注入和自旋输运的关键的第一步。在这里，我们研究了Co与SL MoS_2的接触，发现加入薄的氧化物势垒(MgO)可以显著降低肖特基势垒高度。此外，我们还证明了通过调节后栅载流子密度可以将势垒高度降低到零。因此，氧化镁可以同时提供隧道势垒，以减轻电导失配，同时最小化接触附近的载流子耗尽。这种对势垒高度的控制应该允许对触点进行仔细的设计，以实现在这些材料中的自旋注入。
MoS2 and related metal dichalcogenides (MoSe2, WS2, WSe2) are layered two-dimensional materials that are promising for nanoelectronics and spintronics. For instance, large spinorbit coupling and spin splitting in the valence band of single layer (SL) MoS2 could lead to enhanced spin lifetimes and large spin Hall angles. Understanding the nature of the contacts is a critical first step for realizing spin injection and spin transport in MoS2. Here, we have investigated Co contacts to SL MoS2 and find that the Schottky barrier height can be significantly decreased with the addition of a thin oxide barrier (MgO). Further, we show that the barrier height can be reduced to zero by tuning the carrier density with back gate. Therefore, the MgO could simultaneously provide a tunnel barrier to alleviate conductance mismatch while minimizing carrier depletion near the contacts. Such control over the barrier height should allow for careful engineering of the contacts to realize spin injection in these materials.