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论文题目： 真空冷喷涂制备染料敏化太阳电池纳米二氧化钛电极的工艺研究
学科专业： 材料科学与工程
学位申请人：刘广剑
指导教师： 李长久  教授


摘  要

　　本论文通过粘结剂聚乙二醇团聚纳米二氧化钛粉末制备了微纳米粉末，利用真空冷喷涂工艺制备了染料敏化太阳电池用纳米二氧化钛涂层，探讨了粉末组份、涂层沉积工艺、涂层后处理对真空冷喷涂纳米二氧化钛涂层特性的影响规律。并用纳米二氧化钛涂层组装了染料敏化太阳电池，探讨了真空冷喷涂纳米二氧化钛涂层组织结构对染料敏化太阳电池输出特性的影响。采用X射线衍射仪、扫描电镜、场发射扫描电镜和BET氮气吸附测试仪分析了粉末和涂层的组织结构，采用自行试制的染料敏化太阳电池测试系统分析了电池的输出特性。
　　研究结果表明，纳米结构涂层由亚微米~1μm量级的复合颗粒沉积形成，涂层的增长速度与喷枪移动速度的倒数、沉积层叠次数成正比。涂层厚度可控性良好，可以实现数微米至数百微米厚的纳米结构涂层的制备。
　　涂层的晶体结构与粉末完全相同，真空冷喷涂沉积过程不改变纳米二氧化钛的晶体结构，可完全将粉末的晶体结构移植至涂层，因此，通过粉末结构可以控制涂层结构。复合涂层经过450C热处理去除团聚粘结剂聚乙二醇后，仍然保持了原始纳米二氧化钛粉末的晶体结构，并且具有多孔结构，微孔孔径分布集中在10~40nm，粉末中聚乙二醇的含量对涂层的微孔分布没有显著影响。
　　结果表明，用真空冷喷涂纳米二氧化钛涂层组装的染料敏化太阳电池，在100mW/cm2模拟太阳光强照射下，电池的能量转换效率达到了4.4%。在质量含量不大于41.2%的范围内，粉末中聚乙二醇含量越高，涂层热处理后组装的染料敏化太阳电池的性能越好。涂层厚度对染料敏化太阳电池的性能有显著影响，在本实验研究条件下，最优厚度为11μm左右。四氯化钛后处理涂层能够提高染料敏化太阳电池的性能，能量转化效率增大了47.7%，达到6.5%。




关 键 词：真空冷喷涂，染料敏化太阳电池，纳米二氧化钛涂层
论文类型：应用基础

Title: Preparation of Nano-TiO2 Electrode for Dye-sensitized Solar Cells through Vacuum Cold Spray
Speciality: Materials Processing Engineering
Applicant: Liu Guangjian
Supervisor: Prof. Li Changjiu


ABSTRACT

   In this study, the composite powder in submicron meter size was prepared using nano-TiO2 powder and polyethylene glycol (PEG). The nano-TiO2 coating used for Dye-sensitized Solar Cells (DSC) assembly was prepared through Vacuum Cold Spray (VCS). The influences of the powder constitutions, the deposition parameters and the coating post treatment to the nano-TiO2 coating as well on the deposition characteristics were studied. The DSC was assembled using nano-TiO2 coating prepared by VCS. The influence of the coating micro structure on the cell performance was investigated. The deposition characteristics and the microstructure of the coating are characterized by x-ray diffraction analysis, scanning electron microscopy (SEM), field emission scanning electron microscope (FESEM) and BET method. The performance of the cell was tested under the home-developed DSC testing system.
   The results indicated that, the nano-structured coating was deposited by composite powder in submicron meter particles. The deposition rate is directly proportional to the reciprocal of the transverse speed of the spray gun over the substrate and the number of the spray pass. The coating thickness can be controlled in the range of from several micron meters to several hundreds micron meters.
   The crystalline structure of the coating was the same as that of the starting powder. Through VCS, the original crystalline structure of powder can be completely transferred into the coating. The deposit crystalline structure can be controlled through the design of the starting powder structure. The coating after annealing treatment at 450 ?C for removal of the PEG does not change the crystalline structure of the coating. The removal of PEG leads to the creation of an additional pores in the coating with a distribution of pore size of 10~40nm. The content of the PEG has no remarkable influence on the size of nano pores in the coating.
   The DSC assembled using nano-TiO2 coating prepared by VCS presented a conversion yield of 4.4% under the illumination intensity of 100mW/cm2. The short circuit current density and conversion yield was increased with increasing PEG content in the composite powder. The thickness of nano-TiO2 coating has a significant influence on the performance of the cell, and a DSC cell of nano-TiO2 coating in a thickness about 11 μm will achieve the optional performance. Using nano-TiO2 coating treated by TiCl4 has improved the performance of DSC. The conversion yield was increased by 47.7%, and up to 6.5%.


Keywords: Vacuum Cold Spray, Dye-sensitized Solar Cell, Nano-TiO2 Coating
Thesis type: Application Fundamentals