Textured transparent conductive electrodes for thin-film solar cells have been considered as an effective route for enhancing sunlight harvest due to light trapping. Here, we report a self-assembling electrochemical approach for preparing Al-doped ZnO nanorod arrays (NRAs) as light-trapping electrodes from a mixed aqueous solution of zinc nitrate and aluminium nitrate. The mechanism and optimized process conditions of forming one-dimensional ZnO nanorods with Al-doping were systematically investigated. The results showed that Al atoms were successfully doped into ZnO crystal lattice, and the morphologies could be controlled by adjusting the Al³⁺/Zn²⁺ ratio in the precursors and deposition time. The Al-doped ZnO films grew into well-aligned hexagonal NRAs with c-axis perpendicular to the substrates and then transited into a mixture of nanosheets and nanorods with Al³⁺/Zn²⁺ ratio increasing. They exhibited good electrical conductivity with a sheet resistance of 68-167Ω/square and appropriate visible light transmittance of 61-82%. Taking into account of desired morphology and phase purity, as well as good electrical conductivity and optical transmittance, the optimal window of Al³⁺/Zn²⁺ ratio in the precursors was determined between 1 at% and 2 at% with applied potential of -1.5V, bath temperature of 80°C, and deposition time of about 30min. The electrodeposition method provides a facile and efficient route for obtaining large-area textured transparent electrodes at a low cost.

中文翻译：

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电沉积铝掺杂形成一维ZnO纳米棒的机理及优化工艺条件

用于薄膜太阳能电池的带纹理的透明导电电极已经被认为是用于增强由于光捕获而聚集的阳光的有效途径。在这里，我们报告了一种自组装电化学方法，用于从硝酸锌和硝酸铝的混合水溶液中制备Al掺杂的ZnO纳米棒阵列（NRA）作为光捕获电极。系统研究了铝掺杂形成一维ZnO纳米棒的机理和优化的工艺条件。结果表明，Al原子成功掺杂到ZnO晶格中，通过调节Al ³⁺ / Zn ²⁺可以控制形貌。前驱体中的比率和沉积时间。Al掺杂的ZnO薄膜长成c轴垂直于基板的排列良好的六角形NRA，然后转变为Al ³⁺ / Zn ²⁺比例增加的纳米片和纳米棒的混合物。它们表现出良好的导电性以68-167的薄层电阻Ω /□和适当的可见光的61-82％的透射率。考虑到所需的形态和相纯度，以及良好的电导率和透光率，Al ³⁺ / Zn ²⁺的最佳窗口在-1.5V的施加电势，80°C的浴温和约30分钟的沉积时间下，确定前驱体中的碳原子比为1 at％至2 at％。电沉积方法提供了以低成本获得大面积纹理化透明电极的简便有效途径。