电沉积可控制备ZnO纳米阵列及其光电化学性质研究

发布时间：2018-02-26 10:23

  本文关键词： 电沉积 氧化锌 纳米结构阵列 柔性 染料敏化太阳能电池　出处：《北京科技大学》2015年博士论文　论文类型：学位论文

【摘要】：一维有序氧化锌(ZnO)纳米阵列与分级ZnO纳米阵列以其优越的结构特性,被广泛用作染料敏化太阳能电池(DSSCs)的光阳极材料。本论文采用低温、简捷的电沉积法,在不同基底上可控制备得到不同形貌的ZnO纳米结构阵列,研究了电沉积参数对于ZnO纳米结构阵列合成的影响规律,探讨了不同形貌ZnO纳米结构阵列的光电化学性质。 采用一步电沉积方法,通过调控ZnO纳米棒的生长速度与自侵蚀速度,在FTO基底上制备得到了粒径较小、尺寸均一、取向性好的ZnO纳米管阵列,系统研究了基底预处理、溶液pH值、Zn2+浓度、沉积电位、沉积时间和沉积温度对于可控制备ZnO纳米管阵列的影响,阐明了ZnO纳米管阵列的形成机理。通过调控ZnO纳米管的形貌及结构,实现了对其禁带宽度与光致发光特性的可控调节。探讨了纳米管表面的本证缺陷情况,测试了ZnO纳米管的光电转换性能。结果表明：在pH值为3.70的0.005mol L-1ZnCl2与0.1mol L-1KCl混合前驱液中,-1.3V下沉积10s获得大量ZnO晶核后,-1.0V下沉积1800s可直接制备得到垂直于基底生长,平均直径约为188nm,平均壁厚约为50nm的纳米管阵列。但基于ZnO纳米管阵列的光电转换性能较差,仅为0.06%。 采用电沉积方法,在柔性不锈钢网基底上,制备得到了尺寸均一、取向性好的ZnO纳米棒阵列,详细探讨了沉积参数对于可控制备ZnO纳米棒阵列的影响,实现了ZnO纳米棒阵列的可控制备。研究了不同形貌ZnO纳米棒阵列对DSSCs光电转换效率的影响,初步阐明了两者之间的相互依存关系。结果表明：采用0.0005mol L-1ZnCl2与0.1mol L-1KCl混合前驱液,在-1.O V下沉积1800s,重复沉积3次可使ZnO纳米棒阵列的长度由0.8μm增加至2.2μm,并获得了0.43%的光电转换效率。 采用两步电沉积方法,通过对初级ZnO纳米棒阵列进行胶体铺膜预处理,在柔性不锈钢网基底上制备得到了“花状”结构的分级ZnO纳米棒阵列。次级结构直接生长于初级ZnO纳米棒的表面,平均直径约为78nm,长度约为500nm。探讨了初级结构与次级结构制备参数对于分级结构的影响,研究了基于不锈钢网基底分级ZnO纳米棒阵列光阳极的光电转化效率与相应结构之间的关系。结果表明：在柔性不锈钢网基底上,基于分级ZnO纳米棒阵列的DSSCs相比于初级ZnO纳米棒阵列,其光电转换性能由0.43%提升到了0.72%。采用ZnO纳米粒子修饰分级ZnO纳米棒阵列表面,在60℃下敏化6h后,可进一步将ZnO基DSSCs的光电转换效率提升至1.11%。
[Abstract]:One-dimensional ordered zinc oxide (ZnO) nanoarrays and graded ZnO nanoarrays are widely used as photoanode materials for dye sensitized solar cells due to their excellent structural properties. ZnO nanostructure arrays with different morphologies can be controlled on different substrates. The influence of electrodeposition parameters on the synthesis of ZnO nanostructure arrays is studied, and the photochemical properties of ZnO nanostructures arrays with different morphologies are discussed. By controlling the growth rate and self-erosion rate of ZnO nanorods, a ZnO nanotube array with small particle size, uniform size and good orientation was prepared on FTO substrate by one-step electrodeposition. The substrate pretreatment was systematically studied. The effects of pH value of solution Zn _ 2 concentration, deposition potential, deposition time and deposition temperature on the controllable preparation of ZnO nanotube arrays were discussed. The formation mechanism of ZnO nanotube arrays was elucidated by regulating the morphology and structure of ZnO nanotubes. The band gap and photoluminescence characteristics of the nanotubes are controlled, and the defects on the surface of nanotubes are discussed. The optoelectronic conversion properties of ZnO nanotubes were measured. The results showed that the substrate growth could be directly prepared by depositing a large number of ZnO nuclei at 10s in a mixture of 0.005mol / L ZnCl _ 2 and 0.1mol / L KCl at pH 3.70 for 10 s after depositing a large number of ZnO nuclei after depositing 1800s at -1.0 V, respectively, in the mixed precursor solution of 0.005mol / L ZnCl _ 2 and 0.1mol / L ~ (-1) KCl at pH 3.70. The average diameter is about 188nm, the average wall thickness is about 50nm, but the photoelectric conversion performance based on ZnO nanotube array is poor, only 0.06nm. ZnO nanorod arrays with uniform size and good orientation were prepared on flexible stainless steel mesh substrate by electrodeposition. The effect of deposition parameters on controllable preparation of ZnO nanorod arrays was discussed in detail. The controllable preparation of ZnO nanorod arrays was realized. The effect of ZnO nanorod arrays with different morphologies on the photoelectric conversion efficiency of DSSCs was studied, and the interdependence between them was preliminarily elucidated. The results showed that 0.0005mol L -1 ZnCl 2 and 0.1mol L -1 KCl were used as precursors. The length of ZnO nanorod array was increased from 0. 8 渭 m to 2. 2 渭 m by repeated deposition for 1800s at -1. 0 V, and the photoelectric conversion efficiency of 0.43% was obtained. A two-step electrodeposition method was used to pretreat the primary ZnO nanorods array by colloidal coating. A "flower-like" hierarchical ZnO nanorod array was prepared on a flexible stainless steel mesh substrate. The secondary structure was grown directly on the surface of the primary ZnO nanorods. The average diameter is about 78 nm and the length is about 500 nm. The effects of the preparation parameters of primary and secondary structures on the hierarchical structures are discussed. The relationship between the photoconversion efficiency and the corresponding structure of ZnO nanorod array photoanode based on stainless steel mesh substrates is studied. The results show that: on a flexible stainless steel mesh substrate, Compared with the primary ZnO nanorods array, DSSCs based on graded ZnO nanorod array has improved its photoelectric conversion performance from 0.43% to 0.720.The surface of graded ZnO nanorod array was modified by ZnO nanoparticles and sensitized at 60 鈩，

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