Inversion Symmetry Broken 2D 3R-MoTe2
Inversion Symmetry Broken 2D 3R-MoTe2
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反演对称性破缺 2D 3R-MoTe2
DOI：
10.1002/adfm.201800785
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发表时间：
2018
影响因子：
19
通讯作者：
Zhai TY
中科院分区：
文献类型：
--
作者：
Yang Dan;Hu Xiaozong;Zhou Shasha;Li Aoju;Yu Yiwei;Li Huiqiao;Gan Lin;Zhai Tianyou;Zhuang Minghao;Ding Yao;Luo Zhengtang;Gan L;Zhai TY
反转对称破缺3R相半导体过渡金属二硫属化物（TMDC）由于其强自旋-轨道耦合，特别是不受层数限制的非中心对称结构，在谷电子学和非线性光学等新领域有着巨大的应用潜力。遗憾的是，迄今为止，3R相TMDC的制造仍然是一个巨大的任务。碲化钼（MoTe 2）由于其各相之间的易转变性和接近硅的窄带隙，近年来引起了越来越多的关注。然而，弱的Mo-Te键和相之间的小能量不平等使得获得纯相单晶MoTe 2具有很大的挑战，特别是;获得二维（2D）3R-MoTe 2仍然是一块处女地。在此，通过合理控制沉积温度和碲化速度，首次通过化学气相沉积从MoCl 5前体合成了高质量的2D 3R-MoTe 2薄片。扫描透射电子显微镜明确揭示了合成MoTe 2的3R堆叠模式。二次谐波产生测量证实了出色的奇/偶层独立频率转换效率。此外，还展示了合成的3R-MoTe 2的出色的固有红外探测能力。
Inversion symmetry broken 3R phase semiconducting transition metal dichalcogenides (TMDC) have huge potential applications in many novel fields, such as valleytronics and nonlinear optics for the strong spin–orbit coupling and particularly the persistent noncentrosymmetric structure regardless the layer numbers, in stark contrast to the strict layer number requirement in other phases. Unfortunately, the fabrication of 3R phase TMDC is still a huge task to date. Molybdenum telluride (MoTe2) attracts increasing interest in recent years due to the easy transition between its various phases and its narrow bandgap close to silicon. However, the weak Mo–Te bond and the small energy imparity among phases make it a big challenge to obtain pure‐phase single crystalline MoTe2, especially; it is still a virgin land to obtain two‐dimensional (2D) 3R‐MoTe2. Here, by rational controlling the deposition temperature and tellurization velocity, for the first time high quality 2D 3R‐MoTe2flakes are synthesized via chemical vapor deposition from a MoCl5precursor. Scanning transmission electron microscopy unambiguously reveals the 3R stacking mode of as‐synthesized MoTe2. Second harmonic generation measurement confirms the excellent odd/even layer‐independent frequency conversion efficiency. Besides, the outstanding intrinsic infrared detection ability of as‐synthesized 3R‐MoTe2is demonstrated as well.