ZnO透明导电纳米线阵列的可控生长研究

发布时间：2018-06-10 19:09

  本文选题：染料敏化太阳电池 + 透明导电氧化物　； 参考：《长沙理工大学》2015年硕士论文

【摘要】：透明导电氧化物(Transparent Conductive Oxide,TCO)薄膜是一类比较有特色的功能材料,它同时具有两种突出的性质:可见光透明性和导电性。未掺杂的金属氧化物属于半导体,导电性能不是很好,一般可以通过掺杂或者其他缺陷化学原理增强其导电性。一维ZnO纳米线阵列,由于纳米线尺寸与可见光波尺寸相当,因此具有陷光结构效应,可应用于薄膜太阳电池的透明电极,但单晶纳米线掺杂是一个难点。本文使用电化学沉积的方法,在透明导电玻璃基底低成本、大面积制备Al掺杂ZnO透明导电纳米线阵列。采用扫描电子显微镜、X-射线衍射仪、能谱分析仪等手段对样品的表面微观结构、物相组成及形貌进行表征与分析,结合循环伏安谱分析薄膜生长机理。经过比较分析,进而确定电化学反应过程中较佳的Zn2+、Al3+离子浓度、电位大小、极板间距离、温度等实验条件,从而得到最优性能的透明导电ZnO纳米线阵列薄膜,最终实现对Al掺杂ZnO透明导电纳米线阵列的可控生长。获得以下几个方面的结论:(1)电化学沉积ZnO过程中电化学反应、沉淀-溶解、成核-生长三个过程共同决定晶粒形貌,在溶液浓度0.003mol/L、沉积温度70~80℃、极板间距离2cm、沉积电位-1.6~-1.4V之间最有利于长成纳米线阵列,Al掺杂将影响ZnO纳米线阵列的择优生长取向性、形貌及性能。(2)证实Zn(NO_3)_2-Al(NO_3)_3水溶液体系与Zn(NO_3)_2-In(NO_3)_3水溶液体系中电沉积ZnO存在很大的差别。前者可以共沉积制备Al掺杂ZnO纳米线阵列,而后者只能单独沉积出ZnO或In2O3,这可能是Zn(OH)2和In(OH)3溶度积差值较大的缘故。(3)得出实现Al掺杂ZnO透明导电纳米线阵列可控生长的工艺条件,当Al/Zn=1at.%,电沉积时间为60min,阴极还原电位U=-1.5V时,获得结构与性能较优的Al掺杂ZnO透明导电纳米线阵列。(4)比较了四氯化钛与钛酸四丁酯分别作为前驱体溶胶-凝胶法合成TiO_2薄膜的工艺,由于后者的溶胶更容易形成连续网络的[-Ti-O-]n链,制得薄膜更加均匀致密、不容易开裂、导电性较优,更适合于在Al掺杂ZnO透明导电纳米线阵列表面修饰一层细颗粒TiO_2膜。
[Abstract]:Transparent conductive oxide (TCO) thin films are a kind of special functional materials, which have two outstanding properties: transparency of visible light and conductivity. Undoped metal oxides belong to semiconductors and their electrical conductivity is not very good, which can be enhanced by doping or other defect chemical principles. One-dimensional ZnO nanowire arrays have trapping structure effect due to the same size of nanowires and visible light waves, so they can be used as transparent electrodes for thin film solar cells, but the doping of single crystal nanowires is a difficult problem. In this paper, Al-doped ZnO transparent conductive nanowire arrays were prepared by electrochemical deposition on transparent conductive glass substrates with low cost and large area. The surface microstructure, phase composition and morphology of the samples were characterized and analyzed by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and energy spectrum analyzer (EDS). The growth mechanism of the films was analyzed by cyclic voltammetry. Through comparison and analysis, the optimum experimental conditions such as Zn ~ (2 +) ~ (2 +) Al _ (3) ion concentration, potential, distance between plates and temperature were determined, and the transparent conducting ZnO nanowire array films with optimal performance were obtained. Finally, the controllable growth of Al doped ZnO transparent conductive nanowire arrays is realized. The following conclusions are obtained: (1) Electrochemical reaction, precipitation, dissolution, nucleation and growth of ZnO determine the grain morphology in the solution concentration of 0.003 mol / L, and the deposition temperature is 70 ~ 80 鈩，

本文编号：2004289