Erts Donats, Polyakov Boris, Daly Brian, Morris Michael A, Ellingboe Susan, Boland John, Holmes Justin D
Department of Chemistry, Materials Section and Supercritical Fluid Centre, University College Cork, Cork, Ireland.
J Phys Chem B. 2006 Jan 19;110(2):820-6. doi: 10.1021/jp055309p.
The conductive properties of vertically aligned germanium nanowires, with mean diameters of 50 and 100 nm, within anodized aluminum oxide (AAO) templates have been characterized by conductive atomic force microscopy (C-AFM) and macrocontact measurements. C-AFM was used to determine the electrical transport properties of individual nanowires within the arrays, while macrocontacts were used to measure the mean current-voltage characteristics of groups of nanowires. Contact resistance between the nanowires and metal macrocontacts was minimized by polishing and gradual etching of the AAO surface, to expose the nanowires, prior to deposition of the contacts. Impedance measurements were used to analyze the importance of defects on the charge transport properties of the germanium nanowire arrays. Conductivity data from C-AFM and macrocontact measurements were found to be comparable suggesting that both methods are inherently suitable for evaluating the electrical transport properties of encapsulated nanowires within a matrix. These results are significant as the ability to make good ohmic contacts to nanowires, within well-defined arrays, is key for the future "bottom-up" fabrication of multilayered device architectures for future electronic and optoelectronic devices.
采用导电原子力显微镜（C-AFM）和宏观接触测量法，对平均直径为50纳米和100纳米、位于阳极氧化铝（AAO）模板内的垂直排列锗纳米线的导电特性进行了表征。C-AFM用于确定阵列中单个纳米线的电输运特性，而宏观接触用于测量纳米线组的平均电流-电压特性。在沉积接触之前，通过对AAO表面进行抛光和逐步蚀刻以暴露纳米线，从而使纳米线与金属宏观接触之间的接触电阻最小化。采用阻抗测量法来分析缺陷对锗纳米线阵列电荷输运特性的重要性。发现C-AFM和宏观接触测量得到的电导率数据具有可比性，这表明这两种方法本质上都适用于评估基质中封装纳米线的电输运特性。这些结果意义重大，因为在明确界定的阵列中与纳米线形成良好的欧姆接触的能力，是未来用于电子和光电器件的多层器件架构“自下而上”制造的关键。
