Determination of band alignment in the single-layer MoS2/WSe2 heterojunction.
Determination of band alignment in the single-layer MoS2/WSe2 heterojunction.
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DOI：
10.1038/ncomms8666
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发表时间：
2015-07-16
影响因子：
16.6
通讯作者：
Li LJ
中科院分区：
文献类型：
--
作者：
Chiu MH;Zhang C;Shiu HW;Chuu CP;Chen CH;Chang CY;Chen CH;Chou MY;Shih CK;Li LJ
二维电子材料的出现激发了基于过渡金属二硫属化合物异质结构的新型电子和光子器件的提出。在这里，我们报告的过渡金属dichalcogenides异质结的带偏移的测定，通过使用微束X射线光电子能谱和扫描隧道显微镜/光谱。我们确定了II型之间的对齐MoS 2和WSe 2的价带偏移值为0.83 eV和0.76 eV的导带偏移。第一性原理计算表明，在这种异质结构与不同的硫族元素原子，电子结构的WSe 2和MoS 2被很好地保留在各自的层间耦合由于弱。此外，从密度泛函理论得到的价带偏移为0.94 eV，与实验测定一致。 异质结构中相邻材料的带隙的对准在很大程度上决定了器件的电子特性。在这里，作者测量了两种二维材料：二硫化钼和二硒化钨之间的界面处的导带和价带偏移。
The emergence of two-dimensional electronic materials has stimulated proposals of novel electronic and photonic devices based on the heterostructures of transition metal dichalcogenides. Here we report the determination of band offsets in the heterostructures of transition metal dichalcogenides by using microbeam X-ray photoelectron spectroscopy and scanning tunnelling microscopy/spectroscopy. We determine a type-II alignment between MoS2 and WSe2 with a valence band offset value of 0.83 eV and a conduction band offset of 0.76 eV. First-principles calculations show that in this heterostructure with dissimilar chalcogen atoms, the electronic structures of WSe2 and MoS2 are well retained in their respective layers due to a weak interlayer coupling. Moreover, a valence band offset of 0.94 eV is obtained from density functional theory, consistent with the experimental determination. The alignment of the bandgap of adjacent materials in a heterostructure largely determines the electronic properties of a device. Here, the authors measure the conduction and valance band offsets at the interface between two two-dimensional materials: molybdenum disulphide and tungsten diselenide.