Strain distributions and their influence on electronic structures of WSe2-MoS2 laterally strained heterojunctions
Strain distributions and their influence on electronic structures of WSe2-MoS2 laterally strained heterojunctions
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WSe2-MoS2横向应变异质结的应变分布及其对电子结构的影响
DOI：
10.1038/s41565-017-0022-x
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发表时间：
2018
影响因子：
38.3
通讯作者：
Shih Chih-Kang
中科院分区：
文献类型：
--
作者：
Zhang Chendong;Li Ming-Yang;Tersoff Jerry;Han Yimo;Su Yushan;Li Lain-Jong;Muller David A.;Shih Chih-Kang
单层过渡金属二硫化物异质结，包括垂直和横向p-n结，由于其在电子和光电子领域的潜在应用而引起了人们的广泛关注。原子突发性横向异质结（如WSe2-MoS2）中的晶格失配应变为调整其电子特性提供了一种新的能带工程策略。然而，这种方法需要了解应变分布及其对能带对准的影响。在这里，我们使用扫描隧道显微镜研究了wse2 - mos2横向异质结，并对其波纹图进行了成像，以高空间分辨率绘制了完整的二维应变张量。利用扫描隧穿光谱，我们测量了wse2 - mos2横向异质结的应变和能带对准。我们发现错配应变诱导了II型到I型的带对准转变。扫描透射电镜显示界面处的位错部分缓解了应变。最后，由于异质键的作用，我们在界面处观察到一个独特的电子结构。
Monolayer transition metal dichalcogenide heterojunctions, including vertical and lateral p–n junctions, have attracted considerable attention due to their potential applications in electronics and optoelectronics. Lattice-misfit strain in atomically abrupt lateral heterojunctions, such as WSe2–MoS2, offers a new band-engineering strategy for tailoring their electronic properties. However, this approach requires an understanding of the strain distribution and its effect on band alignment. Here, we study a WSe2–MoS2lateral heterojunction using scanning tunnelling microscopy and image its moiré pattern to map the full two-dimensional strain tensor with high spatial resolution. Using scanning tunnelling spectroscopy, we measure both the strain and the band alignment of the WSe2–MoS2lateral heterojunction. We find that the misfit strain induces type II to type I band alignment transformation. Scanning transmission electron microscopy reveals the dislocations at the interface that partially relieve the strain. Finally, we observe a distinctive electronic structure at the interface due to hetero-bonding.