Center for Bits and Atoms, The Media Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Nat Mater. 2011 Jul 10;10(8):596-601. doi: 10.1038/nmat3069.
Rational control over the morphology and the functional properties of inorganic nanostructures has been a long-standing goal in the development of bottom-up device fabrication processes. We report that the geometry of hydrothermally grown zinc oxide nanowires can be tuned from platelets to needles, covering more than three orders of magnitude in aspect ratio (~0.1-100). We introduce a classical thermodynamics-based model to explain the underlying growth inhibition mechanism by means of the competitive and face-selective electrostatic adsorption of non-zinc complex ions at alkaline conditions. The performance of these nanowires rivals that of vapour-phase-grown nanostructures, and their low-temperature synthesis (<60 °C) is favourable to the integration and in situ fabrication of complex and polymer-supported devices. We illustrate this capability by fabricating an all-inorganic light-emitting diode in a polymeric microfluidic manifold. Our findings indicate that electrostatic interactions in aqueous crystal growth may be systematically manipulated to synthesize nanostructures and devices with enhanced structural control.
理性控制无机纳米结构的形态和功能特性一直是自下而上的器件制造工艺发展的长期目标。我们报告说，水热生长的氧化锌纳米线的几何形状可以从板片调变为针状，纵横比（~0.1-100）超过三个数量级。我们引入了一个基于经典热力学的模型，通过在碱性条件下竞争和选择性地静电吸附非锌络合离子，解释了这种生长抑制的内在机制。这些纳米线的性能可与气相生长的纳米结构相媲美，其低温合成（<60°C）有利于复杂和聚合物支撑器件的集成和原位制造。我们通过在聚合物微流控歧管中制造全无机发光二极管来说明这种能力。我们的研究结果表明，在水相晶体生长中的静电相互作用可以被系统地操纵，以合成具有增强结构控制的纳米结构和器件。
