Charge Transport in MoS2/WSe2 van der Waals Heterostructure with Tunable Inversion Layer
Charge Transport in MoS2/WSe2 van der Waals Heterostructure with Tunable Inversion Layer
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DOI：
10.1021/acsnano.7b00021
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发表时间：
2017-04-01
期刊：
影响因子：
17.1
通讯作者：
Lee, Young Hee
中科院分区：
文献类型：
--
作者：
Doan, Manh-Ha;Jin, Youngjo;Lee, Young Hee
尽管对二维货车德瓦尔斯异质结构进行了大量研究，但对这些结构中的电荷传输和光致电流机制的充分理解，特别是与界面处的电荷耗尽/反型层相关的机制仍然是难以捉摸的。在这里，我们通过可调电荷反转/耗尽层研究了原型多层MoS 2/WSe 2异质结的输运特性。由于WSe 2的掺杂浓度相对于MoS 2的掺杂浓度较低，因此在WSe 2的表面处构造了电荷反转层，这可以通过背栅偏压来调节。耗尽区被限制在几个纳米内的MoS 2侧，而电荷完全耗尽的整个WSe 2侧，这是由拉曼光谱和运输测量。通过异质结的电荷输运的反型层的存在下的影响，并涉及两个制度的隧穿和复合。此外，光电流测量清楚地揭示了复合和空间电荷限制的行为，类似于那些从有机半导体构建的异质结构。这有助于研究各种其他类型的异质结构，并可进一步应用于电子和光电器件。
Despite numerous studies on two-dimensional van der Waals heterostructures, a full understanding of the charge transport and photoinduced current mechanisms in these structures, in particular, associated with charge depletion/inversion layers at the interface remains elusive. Here, we investigate transport properties of a prototype multilayer MoS2/WSe2 heterojunction via a tunable charge inversion/depletion layer. A charge inversion layer was constructed at the surface of WSe2 due to its relatively low doping concentration compared to that of MoS2, which can be tuned by the back-gate bias. The depletion region was limited within a few nanometers in the MoS2 side, while charges are fully depleted on the whole WSe2 side, which are determined by Raman spectroscopy and transport measurements. Charge transport through the heterojunction was influenced by the presence of the inversion layer and involves two regimes of tunneling and recombination. Furthermore, photocurrent measurements clearly revealed recombination and space-charge-limited behaviors, similar to those of the heterostructures built from organic semiconductors. This contributes to research of various other types of heterostructures and can be further applied for electronic and optoelectronic devices.