Wang Yixiu, Jin Shengyu, Wang Qingxiao, Wu Min, Yao Shukai, Liao Peilin, Kim Moon J, Cheng Gary J, Wu Wenzhuo
School of Industrial Engineering, Purdue University, West Lafayette, IN, 47907, USA.
Flex Laboratory, Purdue University, West Lafayette, IN, 47907, USA.
Nanomicro Lett. 2020 Aug 8;12(1):160. doi: 10.1007/s40820-020-00493-3.
The low-dimensional, highly anisotropic geometries, and superior mechanical properties of one-dimensional (1D) nanomaterials allow the exquisite strain engineering with a broad tunability inaccessible to bulk or thin-film materials. Such capability enables unprecedented possibilities for probing intriguing physics and materials science in the 1D limit. Among the techniques for introducing controlled strains in 1D materials, nanoimprinting with embossed substrates attracts increased attention due to its capability to parallelly form nanomaterials into wrinkled structures with controlled periodicities, amplitudes, orientations at large scale with nanoscale resolutions. Here, we systematically investigated the strain-engineered anisotropic optical properties in Te nanowires through introducing a controlled strain field using a resist-free thermally assisted nanoimprinting process. The magnitude of induced strains can be tuned by adjusting the imprinting pressure, the nanowire diameter, and the patterns on the substrates. The observed Raman spectra from the chiral-chain lattice of 1D Te reveal the strong lattice vibration response under the strain. Our results suggest the potential of 1D Te as a promising candidate for flexible electronics, deformable optoelectronics, and wearable sensors. The experimental platform can also enable the exquisite mechanical control in other nanomaterials using substrate-induced, on-demand, and controlled strains.
一维(1D)纳米材料的低维、高度各向异性几何结构以及优异的机械性能,使得其能够实现精细的应变工程,具备了块体材料或薄膜材料所无法企及的广泛可调性。这种能力为在一维极限下探索有趣的物理学和材料科学带来了前所未有的可能性。在用于在一维材料中引入可控应变的技术中,使用压花衬底的纳米压印因其能够以纳米级分辨率大规模地将纳米材料平行形成具有可控周期性、振幅和取向的褶皱结构而受到越来越多的关注。在此,我们通过使用无抗蚀剂热辅助纳米压印工艺引入可控应变场,系统地研究了碲纳米线中应变工程化的各向异性光学性质。可以通过调节压印压力、纳米线直径和衬底上的图案来调整诱导应变的大小。从一维碲的手性链晶格观察到的拉曼光谱揭示了应变下强烈的晶格振动响应。我们的结果表明,一维碲作为柔性电子学、可变形光电子学和可穿戴传感器的有前途的候选材料具有潜力。该实验平台还能够利用衬底诱导的、按需的和可控的应变,在其他纳米材料中实现精细的机械控制。