Efficient and Chiral Electroluminescence from In‐Plane Heterostructure of Transition Metal Dichalcogenide Monolayers
Efficient and Chiral Electroluminescence from In‐Plane Heterostructure of Transition Metal Dichalcogenide Monolayers
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DOI：
10.1002/adfm.202203602
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发表时间：
2022-07
影响因子：
19
通讯作者：
Naoki Wada;J. Pu;Yuhei Takaguchi;Wenjin Zhang;Zheng Liu;T. Endo;T. Irisawa;K. Matsuda;Y. Miyauchi;T. Takenobu;Y. Miyata
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文献类型：
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作者：
Naoki Wada;J. Pu;Yuhei Takaguchi;Wenjin Zhang;Zheng Liu;T. Endo;T. Irisawa;K. Matsuda;Y. Miyauchi;T. Takenobu;Y. Miyata
原子薄过渡金属二硫族化物（TMDCs）由于其优异的电学、光学和量子（自旋谷）特性，在未来的光电子应用中具有吸引力。特别是，基于TMDC单层的平面异质结构提供了通过组成元素的空间分布直接调制能带结构和晶格应变的机会，从而有效地控制它们的载流子输运和重组。然而，由于样品/器件制造的技术困难，使用这种平面异质结构制造发光器件仍然具有挑战性。本研究证明了不同的TMDC单层平面异质结构中的界面电致发光（EL）。采用化学气相沉积的方法，生长出具有尖锐界面的大面积单晶平面异质结构的各种组合，然后采用基于电解质的发光器件来观察EL。良好的异质结构使得沿结界面固定的线性EL能够捕获。值得注意的是，在室温下，WS2/WSe2平面异质结构表现出圆极化的EL，极化率为10%。这可以用界面应变介导的电子结构演化来解释，其中电场和应变诱导谷漂移的结合实现了K/K '谷的选择性EL。这些发现为扩大单层平面内异质结构在功能光电器件中的应用潜力铺平了道路。
Atomically thin transition metal dichalcogenides (TMDCs) are attractive materials for future optoelectronic applications because of their excellent electrical, optical, and quantum (spin‐valley) properties. In particular, in‐plane heterostructures based on TMDC monolayers provide opportunities to directly modulate band structures and lattice strains by the spatial distribution of constituent elements, leading to efficient control of their carrier transport and recombination. However, it is still challenging to create light‐emitting devices using such in‐plane heterostructures because of the technical difficulties associated with sample/device fabrication. This study demonstrated interfacial electroluminescence (EL) in diverse TMDC monolayer in‐plane heterostructures. Various combinations of large‐area, single‐crystalline in‐plane heterostructures with sharp interfaces are grown by chemical vapor deposition, followed by the adoption of electrolyte‐based light‐emitting devices to observe EL. The fine heterostructures enabled the capture of the linear‐shaped EL fixed along the junction interfaces. Significantly, the WS2/WSe2 in‐plane heterostructures exhibited circularly polarized EL with polarizability of 10% at room temperature. This can be explained by the interfacial strain‐mediated electronic structure evolution, in which the combination of electric fields and strain‐induced valley drifts realizes selective EL from the K/K’ valley. These findings pave the way for expanding the potential of monolayer in‐plane heterostructures for use in functional optoelectronic devices.