【作者】 程鹏飞；

【导师】 郑杰； 卢革宇；

【作者基本信息】 吉林大学 ， 物理电子学， 2014， 博士

【摘要】 世界能源问题主要是能源短缺与需求之间的矛盾以及能源利用与环境保护之间的矛盾。非再生能源的大量开采和利用，已经使其濒临枯竭。因此，人们将目光投向新型、清洁的可再生能源。其中，太阳能作为巨大和永恒的清洁可再生能源已成为人类最优先考虑开发的能源之一。太阳能的利用本质上是将光能转换为可利用的能量形式，例如，电能和热能，其中，基于光电转化原理的太阳能电池可直接将光能转换为电能，并且具有较高的理论转换效率，因此受到广泛关注。太阳能电池发展至今，已经发展到第三代，在第三代光伏器件当中，染料敏化太阳能电池（DSSCs）具有转换效率较高、制作工艺简单、成本较低、制作能耗回收周期较短等优点，被认为是第三代太阳能电池中最具潜力的候选者之一。在DSSCs电池结构中，光阳极材料发挥如下作用：一是作为染料的载体，二是作为入射光散射的媒介，三是作为载流子传输的平台，因此要求其具有大的比表面积、适中的尺寸和结构以及良好的导电性。TiO2不仅具有和染料匹配的能级位置和禁带宽度，而且具有上述的优良特性，因此是目前为止研究最多的光阳极材料。分等级结构TiO2兼具大比表面积和优良的光电特性，其设计、制备以及在构建高性能光阳极结构中的应用已成为近些年来国内外研究的热点。本论文面向高性能DSSCs光阳极的构筑，系统开展了分等级结构TiO2的设计和可控制备、新型光阳极结构的设计与制作以及TiO2的结构与电池特性间关系的研究。具体研究内容包括：（1）为了提高TiO2的比表面积和光电特性，以商用的P25TiO2粉体作为出发原料，在强碱环境下，通过不添加与添加双氧水，利用水热合成方法分别成功地制备出具有超大比表面积的三维纳米筛结构（nanomesh structure）和海胆状结构（urchin-like structure）TiO2纳米材料（424m2g-1和392m2g-1）。并以所制备的分等级结构的TiO2作为光散射层、P25作为透过层、P25+分等级结构作为混合层构建了新型的TiO2光阳极结构，DSSCs的光电转换效率的提升幅度分别为47%和36%。（2）融合水热生长和强碱腐蚀方法，在FTO衬底上成功地制备出顶层为TiO2纳米花冠、底层是TiO2纳米森林（TC-BF）的复合纳米结构，对其进行了形貌（SEM、TEM）和结构（XRD）表征。利用所制备的新颖光阳极结构制作了DSSCs，发现纳米森林密度最大的光阳极具有最大的光电转换效率，可归因于其光散射、染料吸附以及电子传输等性能的大幅度提升。（3）以钛酸四正丁酯为钛源，以二乙撑三胺为结构导向剂，利用水热合成法制备了具有核壳结构的介孔TiO2，以上述材料为散射层、P25为透过层制作了光阳极。由于核壳结构的“光阱”作用，光散射效果显著提升，介孔结构增强了对染料的吸附能力，所制备TiO2分等级结构的双重特性使得DSSCs的光电性能明显提升，与单纯的P25相比，光电转换效率上升了38%。更多还原

【Abstract】 The world’s energy problems are mainly the contradiction between the shortageof energy and the demand and the contradiction between the energy utilizationand theenvironment. The excessive exploitation and utilization has caused thenon-renewableenergy to the verge of extinction. Therefore, People turned their attention to the new,clean and renewable energy. However, solar energy is one of hailed renewable energywith endless and clean. The optical energy is converted into a form of availableenergy on the nature of the solar energy, for example, electric energy and thermalenergy. The utilization of solar energy is the production of the solar cells which baseon photoelectric conversion principle, and is widespread concerned with hightheoretical conversion efficiency. Since the development of solar cells, dye sensitizedsolar cells (DSSCs) with prominent superiority and recognized high photoelectricconversion efficiency have been received widespread attention among the thirdgeneration of photovoltaic devices, and considered to be one of the most promisingcandidates in solar cells.In DSSCs structures, photoanode plays the following effects: Firstly, as a carrierof the dye, secondly, as a medium for scattering of the incident light, thirdly, as aplatform of the teleportation. Therefore, require it to have a large specific surface area,a temperate size and structure, and a good conductivity. As the preferred photoanodefilm materials of DSSCs, TiO2has the proper position of the band gap and energylevels, and has the excellent characteristics above. In recent years, the design andfabrication of hierarchical structure TiO2based on large specific surface area andexcellent optoelectronic properties for DSSCs are becoming research focus. In this paper, micro/nano-TiO2materials synthesis, fabrication and assembly processes ofDSSCs devices for technical support. In order to construct high specific surface areaand the strong scattering capacity of TiO2photoanode films structure. Thus achievethe ultimate goal for providing an experimental basis and theoretical guidance for therealization of high-performance photoanode films and efficient TiO2-based DSSCs.The specific studies include:(1) Commercial P25TiO2powder was used as a precursor, when the alkalisolution was without and with adding hydrogen peroxide (H2O2), the commercialTiO2nanoparticles (P25) were modified under hydrothermal conditions, in order toincrease the surface area and the optoelectronic properties of TiO2. To prepare3Dnanomesh structure and urchin-like structure TiO2nanomaterials with high specificsurface area (424m2g-1and392m2g-1). Prepared TiO2hierarchical structures wereused as scattering layer, P25was used as transparent layer, P25+hierarchicalstructures were used as blended layer to construct the new types of TiO2photoanodestructure, the energy conversion efficiency of DSSCs with these two structurematerials and special structure photoanodes have47%and36%increase comparedto those of P25electrode, respectively.(2) Combine the hydrothermal growth and alkali corrosion methods, aninnovative development of novel double layered photoanodes made of hierarchicalTiO2micro-corollas as the overlayer and TiO2nanoforest as the underlayer (TC-BF)on FTO (Fluorine-doped tin oxide) glass substrate for dye-sensitized solar cells(DSSCs) was developed. The different morphologies TC-BF double layeredphotoanodes with different conditions are characterized by SEM, TEM and XRD, andthen DSSCs devices are assembled and the photoelectricity characteristics are furtherdiscussed. It was found that the maximum density nano-forest photoanode had thehighest energy conversion efficiency, which due to its the most superior performanceon light scattering, dye adsorption and electronic transmission.(3) Tetra-n-butyl Titanate (TBT) was used as the titanium source, anddiethylenetriamine (DETA) was used as the structure-directing agent, core-shell structure materials with mesoporous were synthesized through hydrothermal method.Prepared TiO2above were used as scattering layer, P25was used as transparent layer,and the photoanodes were built with them. The optical path of the incident light iscontrolled by using core-shell structure and this unique structure act as a―light trap‖,scattering effect improved significantly. Meanwhile, the pores of mesoporousstructure can provide more dye adsorption, base on the factors above, thephotoelectricity performances of DSSCs devices are enhanced greatly. The energyconversion efficiency of the DSSCs had a38%increase compared to those of P25electrode.更多还原