Two-dimensional semiconductor HfSe2 and MoSe2/HfSe2 van der Waals heterostructures by molecular beam epitaxy
Two-dimensional semiconductor HfSe2 and MoSe2/HfSe2 van der Waals heterostructures by molecular beam epitaxy
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DOI：
10.1063/1.4917422
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发表时间：
2015-04-06
影响因子：
4
通讯作者：
Dimoulas, A.
中科院分区：
文献类型：
--
作者：
Aretouli, K. E.;Tsipas, P.;Dimoulas, A.
使用分子束外延，在 AlN(0001)/Si(111) 衬底上生长原子级薄的二维半导体 HfSe2 和 MoSe2/HfSe2 范德华异质结构。 HfSe2 的电子能带结构的细节通过原位角分辨光电子能谱成像，表明具有高质量的外延层。第一原理计算支持的高分辨率表面隧道显微镜提供了有序 Se 吸附层的证据，与理论预测相比，这可能是 HfSe2 测量功函数降低的原因。后者的减少最大限度地减少了 HfSe2 和 MoSe2 层之间的功函数差异，导致 MoSe2/HfSe2 异质界面处的价带偏移仅为 0.13 eV，并且 II 型能带排列较弱。 (C) 2015 AIP 出版有限责任公司。
Using molecular beam epitaxy, atomically thin 2D semiconductor HfSe2 and MoSe2/HfSe2 van der Waals heterostructures are grown on AlN(0001)/Si(111) substrates. Details of the electronic band structure of HfSe2 are imaged by in-situ angle resolved photoelectron spectroscopy indicating a high quality epitaxial layer. High-resolution surface tunneling microscopy supported by first principles calculations provides evidence of an ordered Se adlayer, which may be responsible for a reduction of the measured workfunction of HfSe2 compared to theoretical predictions. The latter reduction minimizes the workfunction difference between the HfSe2 and MoSe2 layers resulting in a small valence band offset of only 0.13 eV at the MoSe2/HfSe2 heterointerface and a weak type II band alignment. (C) 2015 AIP Publishing LLC.