Murillo Gonzalo, Lozano Helena, Cases-Utrera Joana, Lee Minbaek, Esteve Jaume
Department of Nano and Microsystems, Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), 08193, Bellaterra, Spain.
Department of Physics, Inha University, Incheon, 22212, South Korea.
Nanoscale Res Lett. 2017 Dec;12(1):51. doi: 10.1186/s11671-017-1838-x. Epub 2017 Jan 18.
This paper presents a study about the dependence of the hydrothermal growth of ZnO nanowires (NWs) with the passivation level of the active surface of the Au catalyst layer. The hydrothermal method has many potential applications because of its low processing temperature, feasibility, and low cost. However, when a gold thin film is utilized as the seed material, the grown NWs often lack morphological homogeneity; their distribution is not uniform and the reproducibility of the growth is low. We hypothesize that the state or condition of the active surface of the Au catalyst layer has a critical effect on the uniformity of the NWs. Inspired by traditional electrochemistry experiments, in which Au electrodes are typically activated before the measurements, we demonstrate that such activation is a simple way to effectively assist and enhance NW growth. In addition, several cleaning processes are examined to find one that yields NWs with optimal quality, density, and vertical alignment. We find cyclic voltammetry measurements to be a reliable indicator of the seed-layer quality for subsequent NW growth. Therefore, we propose the use of this technique as a standard procedure prior to the hydrothermal synthesis of ZnO NWs to control the growth reproducibility and to allow high-yield wafer-level processing.
本文介绍了一项关于氧化锌纳米线（NWs）水热生长与金催化剂层活性表面钝化水平之间关系的研究。水热法因其较低的加工温度、可行性和低成本而具有许多潜在应用。然而，当使用金薄膜作为籽晶材料时，生长出的纳米线通常缺乏形态均匀性；它们的分布不均匀，生长的可重复性较低。我们推测，金催化剂层活性表面的状态或条件对纳米线的均匀性有关键影响。受传统电化学实验的启发，在传统电化学实验中，金电极通常在测量前进行活化，我们证明这种活化是有效辅助和增强纳米线生长的一种简单方法。此外，还研究了几种清洗工艺，以找到一种能产生具有最佳质量、密度和垂直排列的纳米线的工艺。我们发现循环伏安测量是后续纳米线生长的籽晶层质量的可靠指标。因此，我们建议在水热合成氧化锌纳米线之前使用该技术作为标准程序，以控制生长的可重复性并实现高产率的晶圆级加工。
