Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371, Singapore.
Nano Lett. 2014 Aug 13;14(8):4342-51. doi: 10.1021/nl501163n. Epub 2014 Jul 7.
Controlling the morphology of nanowires in bottom-up synthesis and assembling them on planar substrates is of tremendous importance for device applications in electronics, photonics, sensing and energy conversion. To date, however, there remain challenges in reliably achieving these goals of orientation-controlled nanowire synthesis and assembly. Here we report that growth of planar, vertical and randomly oriented tin-doped indium oxide (ITO) nanowires can be realized on yttria-stabilized zirconia (YSZ) substrates via the epitaxy-assisted vapor-liquid-solid (VLS) mechanism, by simply regulating the growth conditions, in particular the growth temperature. This robust control on nanowire orientation is facilitated by the small lattice mismatch of 1.6% between ITO and YSZ. Further control of the orientation, symmetry and shape of the nanowires can be achieved by using YSZ substrates with (110) and (111), in addition to (100) surfaces. Based on these insights, we succeed in growing regular arrays of planar ITO nanowires from patterned catalyst nanoparticles. Overall, our discovery of unprecedented orientation control in ITO nanowires advances the general VLS synthesis, providing a robust epitaxy-based approach toward rational synthesis of nanowires.
在自下而上的合成中控制纳米线的形态并将其组装到平面衬底上对于电子学、光子学、传感和能量转换等器件应用至关重要。然而，迄今为止，在可靠地实现这些具有定向控制的纳米线合成和组装目标方面仍然存在挑战。在这里，我们报告了通过外延辅助的气-液-固（VLS）机制，通过简单地调节生长条件，特别是生长温度，在氧化钇稳定的氧化锆（YSZ）衬底上可以实现平面、垂直和随机取向的掺锡氧化铟（ITO）纳米线的生长。这种对纳米线取向的强大控制得益于 ITO 和 YSZ 之间 1.6%的小晶格失配。通过使用具有（110）和（111）表面的 YSZ 衬底，除了（100）表面，可以进一步控制纳米线的取向、对称性和形状。基于这些见解，我们成功地从图案化催化剂纳米颗粒中生长出规则排列的平面 ITO 纳米线阵列。总的来说，我们在 ITO 纳米线中发现了前所未有的取向控制，这推进了一般的 VLS 合成，为合理合成纳米线提供了一种基于外延的强大方法。
