Defect-Dominated Doping and Contact Resistance in MoS2
Defect-Dominated Doping and Contact Resistance in MoS2
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DOI：
10.1021/nn500044q
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发表时间：
2014-03-01
期刊：
影响因子：
17.1
通讯作者：
Hinkle, Christopher L.
中科院分区：
文献类型：
--
作者：
McDonnell, Stephen;Addou, Rafik;Hinkle, Christopher L.
实现低电阻接触是实现基于过渡金属二硫族化合物的纳米电子器件的关键。我们发现MoS2的固有缺陷主导了金属/MoS2接触电阻，并提供了一个独立于金属接触功函数的低肖特基势垒。此外，我们发现MoS2可以在同一样品的不同点上同时表现出n型和p型导电。我们通过互补表征技术独立识别了这些区域，并展示了费米能级如何在几十纳米的空间分辨率上移动1 eV。我们发现这些掺杂的变化与缺陷化学有关，与接触金属无关。这对之前关于金属诱导的二硫化钼掺杂的报道提出了质疑，因为与二硫化钼接触的同一金属可以同时表现出n型和p型行为。这些结果可能为通过单一金属沉积实现低电子和空穴肖特基势垒接触提供了一条潜在的途径。
Achieving low resistance contacts is vital for the realization of nanoelectronic devices based on transition metal dichalcogenides. We find that intrinsic defects in MoS2 dominate the metal/MoS2 contact resistance and provide a low Schottky barrier independent of metal contact work function. Furthermore, we show that MoS2 can exhibit both n-type and p-type conduction at different points on a same sample. We identify these regions independently by complementary characterization techniques and show how the Fermi level can shift by 1 eV over tens of nanometers in spatial resolution. We find that these variations in doping are defect-chemistry-related and are independent of contact metal. This raises questions on previous reports of metal-induced doping of MoS2 since the same metal in contact with MoS2 can exhibit both n- and p-type behavior. These results may provide a potential route for achieving low electron and hole Schottky barrier contacts with a single metal deposition.