Strain engineering plays a vital role in controlling the physical properties of two-dimensional (2D) materials. However, the nanomechanical behavior of atomically thin 2D crystals under strain has not been completely understood. Here, strain-induced hierarchical ripple nanostructures in triangular MoS2 flakes were investigated by advanced atomic force microscopy and optical spectral measurements. The hierarchical nanoripples exhibited a threefold radial pattern, and their mechanical, electronic, and optical spectra characteristics were significantly modified due to the suffering from large tensile strain. Structure evolution of these hierarchical nanoripples was further discussed based on the geometry and thickness of MoS2 flakes, and we attributed the curtain effect at the limit of a single atomic layer. Our study will be beneficial in designing nanomechanical structures and prototype electromechanical devices with 2D materials.

中文翻译：

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通过原子力显微镜研究的 MoS2 层中应变诱导的分层波纹

应变工程在控制二维 (2D) 材料的物理特性方面起着至关重要的作用。然而，原子级薄二维晶体在应变下的纳米力学行为尚未完全了解。在这里，通过先进的原子力显微镜和光谱测量研究了三角形 MoS2 薄片中应变诱导的分层波纹纳米结构。分级纳米波纹表现出三重放射状图案，由于承受较大的拉伸应变，它们的机械、电子和光谱特性发生了显着变化。基于 MoS2 薄片的几何形状和厚度进一步讨论了这些分层纳米波纹的结构演变，我们将窗帘效应归因于单个原子层的极限。