Inversion symmetry broken in 2H phase vanadium-doped molybdenum disulfide.
Inversion symmetry broken in 2H phase vanadium-doped molybdenum disulfide.
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DOI：
10.1039/d1nr05725a
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发表时间：
2021-09
期刊：
影响因子：
6.7
通讯作者：
Hanjun Jiang;Lu Zheng;Jing Wang;Manzhang Xu;Xuetao Gan;Xuewen Wang;Wei Huang
中科院分区：
文献类型：
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作者：
Hanjun Jiang;Lu Zheng;Jing Wang;Manzhang Xu;Xuetao Gan;Xuewen Wang;Wei Huang
二维层状过渡金属二硫属化合物（TMDs）由于其独特的晶体结构和二次谐波（SHG）效率在非线性光学应用中受到广泛关注。然而，在TMD的SHG信号显示层依赖的行为，与存在（不存在）的反转对称性在偶数层（奇数层）的TMD。本文中，我们合成了单层和双层2H和3R相钒（V）掺杂的MoS2晶体。使用拉曼光谱、XPS和STEM来鉴定所生长的纳米片的化学组成和晶体结构。利用倍频技术研究了不同堆垛层阶的V掺杂MoS2晶体的对称性。值得注意的是，在双层2H相V掺杂的MoS2的二次谐波效率相当于3R相，表明原位V取代Mo位点引起的反转对称破缺晶格结构。该研究将有助于推动基于二维材料的非线性光学器件的发展。
Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) have received much attention in nonlinear optical applications due to their unique crystal structures and second harmonic generation (SHG) efficiency. However, SHG signals in TMDs show a layer-dependent behavior, consistent with the presence (absence) of inversion symmetry in even-layer (odd-layer) of TMDs. Herein, we synthesized monolayer and bilayer 2H and 3R phase vanadium (V)-doped MoS2 crystal. Raman spectroscopy, XPS, and STEM were used to identify the chemical composition and crystalline structure of as-grown nanoflakes. SHG measurement was used to research the symmetry of V-doped MoS2 crystals with different stacking orders. Significantly, the SHG efficiency in bilayer 2H phase V-doped MoS2 is equivalent to the 3R phase, indicating an inversion symmetry broken lattice structure caused by the in situ V substitute for Mo sites. This study will be conducive to promote the development of promising nonlinear optical devices based on 2D material.