In-Plane Uniaxial Strain in Black Phosphorus Enables the Identification of Crystalline Orientation.
In-Plane Uniaxial Strain in Black Phosphorus Enables the Identification of Crystalline Orientation.
复制标题
DOI：
10.1002/smll.201700466
复制
发表时间：
2017-02
期刊：
影响因子：
13.3
通讯作者：
Shuqing Zhang;Nannan Mao;Juanxia Wu;L. Tong;Jin Zhang;Zhirong Liu
中科院分区：
文献类型：
--
作者：
Shuqing Zhang;Nannan Mao;Juanxia Wu;L. Tong;Jin Zhang;Zhirong Liu
确定各向异性黑磷（BP）的晶轴对于研究其物理性质以及光学和电子应用具有重要意义。在此，它表明，通过施加面内单轴应变和测量的拉曼位移的变化，可以可靠地确定BP的晶轴。应变对拉曼位移的影响是角度依赖的，并且它们可以表示为锯齿形应变和扶手椅应变下的拉曼响应的组合。与以往的偏振光谱法分析拉曼强度不同的是，该方法利用了拉曼频移，其受激光偏振、激发波长、样品厚度和基底的影响较小。从拉伸基板施加在BP上的有效应变估计，结果表明，只有20至40%的应变可以有效地转移到BP薄片从聚对苯二甲酸乙二醇酯基板。我们的方法不仅提供了一个有效的和强大的方法来识别层状BP的晶体取向，但它也是一个模型，以提取额外的信息，在应变相关的研究。它也可以扩展到其他二维各向异性材料。
Identification of the crystalline axis of anisotropic black phosphorus (BP) is important for investigating its physical properties, as well as for optical and electronic applications. Herein, it is showed that by applying in-plane uniaxial strain and measuring the changes of the Raman shifts, the crystalline axis of BP can be reliably determined. The strain effects on the Raman shifts are angle-dependent, and they can be expressed as a combination of the Raman responses under zigzag and armchair strain. Differing from previous polarized optical spectroscopic methods where the Raman intensity is analyzed, the proposed method uses the Raman frequency shift, which is less affected by laser polarization, excitation wavelength, the sample thickness, and the substrate. The effective strain applied on BP from the stretched substrate is estimated, and the results show that only 20 to 40% of the strain can be effectively transferred to BP flakes from a polyethylene terephthalate substrate. Our method provides not only an effective and robust approach to identify the crystalline orientation of layered BP, but it is also a model to extract additional information in strain-related studies. It can also be extended to other 2D anisotropic materials.