两个维的异构结构,多异构结构和超格的强大的表轴生长
Zhengwei Zhang1, Peng Chen1,2, Xidong Duan1
1State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
Science (New York, N.Y.)
|August 5, 2017
概括
研究人员开发了一种新方法,用于种植多种二维 (2D) 原子晶体异构结构,多重异构结构和超级格子. 这种技术确保了稳健的,块对块的表轴生长,具有精确的空间控制和清晰的接口.
科学领域:
- 材料科学
- 纳米技术
- 固态物理
背景情况:
- 二维 (2D) 原子晶体具有独特的电子和光学特性.
- 从这些材料制造复杂的异构结构是由于热降解和不受控制的核化而具有挑战性.
- 精确控制不同二维材料的空间布局对于先进的设备应用至关重要.
研究的目的:
- 从二维原子晶体创建多种横向异构结构,多重异构结构和超级格子的通用和强大的合成策略.
- 在复杂的二维材料组件中实现精确的空间调制和原子利的接口.
- 展示这些工程异构结构在电子设备中的潜力.
主要方法:
- 连续蒸汽沉积增长过程,在温度波动阶段采用反向流量.
- 使用可控冷却来防止热降解和同质核化.
- 使用拉曼和光发光映射,传输电子显微镜 (TEM) 和电传输测量进行表征.
主要成果:
- 成功合成了广泛的2D异构结构 (例如,WS2-WSe2,WS2-MoSe2),多异构结构 (例如,WS2-WSe2-MoS2) 和超级格子 (例如,WS2-WSe2-WS2-WSe2-WS2).
- 实现精确控制的空间调制和原子敏的接口, 通过TEM证实.
- 在WSe2-WS2侧连接处表现出明确的二极管特性,直化率高达105.
结论:
- 开发的反流技术为制造复杂的二维异构结构提供了通用和高度稳固的策略.
- 这种方法可以精确控制材料排列和接口质量.
- 合成的异构结构对未来的设备应用具有有前途的电子特性.
相关概念视频
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01:20Normal Strain under Axial Loading
Normal strain under axial loading is an important concept in the field of mechanics of materials. Axial loading implies the application of a force along the axis of a material, like a column or bar. This force can either compress or stretch the material. In the context of axial loading, normal strain is the deformation experienced by the material in the direction of the loading force. It's calculated as the change in length divided by the original length of the material. This unitless ratio...
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
01:16Eccentric Axial Loading in a Plane of Symmetry
Eccentric axial loading occurs when an axial load is applied away from the centroidal axis of a structural member. This scenario is common in engineering, where structural elements may not be directly aligned due to various design or functional requirements.
01:12General Case of Eccentric Axial Loading
Unsymmetrical bending occurs when the bending moment applied to a structural member does not align with its principal axis. This misalignment leads to complex stress distributions and deflection patterns that differ from symmetrical bending, which are essential for designing structures to withstand different loading conditions.
Consider a member subjected to equal and opposite forces that are applied along a line that does not coincide with the member's neutral axis. In unsymmetrical bending,...
Consider a member subjected to equal and opposite forces that are applied along a line that does not coincide with the member's neutral axis. In unsymmetrical bending,...
01:12Transformation of Plane Strain
When analyzing elongated structures like bars subjected to uniformly distributed loads, it is essential to understand the transformation of plane strain when coordinate axes are rotated. This transformation helps to assess how material deformation characteristics vary with orientation, which is crucial in materials science and structural engineering.
Under plane strain conditions, typical for members where one dimension significantly exceeds the others, deformations and resultant strains are...
Under plane strain conditions, typical for members where one dimension significantly exceeds the others, deformations and resultant strains are...