高效晶体硅太阳电池性能研究

硕士学位论文高效晶体硅太阳电池银硅接触结构力学性能研究学位申请人：陈传科指导教师：杨宏副教授学科名称：凝聚态物理2014 年 05 月Investigation of Mechanical Property for Silver Paste-Si Contact of High Efficient Crystalline Silicon Solar CellsA thesis submitted toXian Jiaotong Universityin partial fulfillment of the requirementsfor the degree ofMaster of ScienceByChuanke ChenSupervisor: Associate Prof. Hong Yang(Condensed Matter Physics)May 2014IV摘 要I论文题目：高效晶体硅太阳电池银硅接触结构力学性能研究学科名称：凝聚态物理学位申请人：陈传科指导教师：杨宏副教授摘 要对于晶体硅太阳电池而言，其前银电极和硅基底之间的力学性能对光伏组件的长期可靠性和使用寿命起着至关重要的作用。银硅接触的性能衰减是导致晶体硅太阳电池及其组件失效的主要原因之一。加之太阳电池的发展趋势正朝着高阻细栅的方向发展，这就要求太阳电池的前银电极栅线的宽度不断减小，即银硅接触面积减小，以达到节约银的用量并增加光线利用率的目的。但是对于目前的太阳电池用银浆来说，随着银栅线的宽度减小，银硅接触的力学性能会急剧退化。如何在保证银硅接触的力学性能的前提下，降低银浆的使用量，节省生产成本，实现光伏发电平价化，并提高太阳电池及其组件的使用寿命和可靠性是当下光伏行业一个迫切亟待解决的问题。本文从理论和实验两个方面着手，深入系统地研究了高效晶体硅太阳电池前电极银硅接触结构的力学性能。理论方面，我们基于结构力学首次建立了银硅接触结构的剪切力与栅线宽度之间的数学模型，并用剪切实验对该模型进行了验证；实验方面，我们研究了太阳电池生产工艺对银硅接触结构附着力的影响，银硅接触界面微观结构对晶体硅太阳电池银硅接触附着力的影响，以及银硅接触结构附着力与太阳电池及其组件功率衰减的关系。通过研究我们发现，晶体硅太阳电池的银硅接触结构的力学性能与栅线的宽度成线性关系，与电池的生产制造工艺以及所选用的材料性能密切相关；同时银厚膜的致密度和银厚膜与硅基底的接触方式对银硅接触结构的力学性能也有重要影响；银硅接触结构的力学性能是影响晶体硅太阳电池及其组件可靠性的关键因素之一，银硅接触力学性能差的组件在户外运行时，其功率衰减程度更大，更容易失效。这些研究成果，为未来太阳电池技术改进以及导电银浆的发展奠定了理论和实验基础。 1关 键 词：太阳电池；银硅接触；附着力；可靠性论文类型：应用研究本研究得到国家自然科学基金项目太阳电池组件寿命预测理论的研究及新的失效机理分析（项目标准号 61274050）资助。西安交通大学硕士学位论文IIABSTRACTIIITitle: Investigation of Mechanical Property for Silver Paste-Si Contact of High Efficient Crystalline Silicon Solar CellsDescipline: Condensed Matter PhysicsApplicant: Chuanke ChenSupervisor: Associate Prof. Hong Yang2ABSTRACTFor crystalline silicon solar cells, the mechanical properties of front metallization are critical to solar modules reliability and long-lifetime. The mechanical properties degradation is one of major factors which cause solar cells and solar modules to failure ahead of time. The development direction of crystalline silicon solar cells is forward to high emitter resistance and compact fingers, this means the width of fingers needs to be more fine to meet the targets of cost saving and increasing utilization rate of light. However, to the silver paste used for photovoltaic, the mechanical properties degradations seriously with the widths of finger finer. In photovoltaic, the urgent problem is not only needs to promote the mechanical properties of Ag-Si contact, but also needs to cut the cost and further develop the reliability and long lifetime of solar cells and solar modules. Therefore, this paper investigates the mechanical properties of Ag-Si contact for crystalline silicon solar cells system from theory and experiment. Firstly, based on Structural Mechanics and Mechanicals of Materials, we have built the mathematical model of Ag-Si contact between the shear force and bus-bar width, and which was verified by shear test. Secondly, the effects of process on interfacial adhesion strength of Ag-Si for crystalline silicon solar cells, the impacts of interface microstructure on adhesion force between silver paste and silicon solar cells emitter, and the effects of binding force between silver paste and silicon on power degradation of crystalline silicon solar modules were investigated respectively. Through above investigations we have gotten some conclusions about the mechanical properties of crystalline silicon solar cell as follows: the shear strength of Ag-Si contact shows a linear relationship with the bus-bar width, and also shows closed relation to process and materials used; the composition of silver paste would affect the interface microstructure and the mechanical property of silver thick-film and Ag/Si contact interface; The binding force reduction between silver paste and silicon leads to power degradation during subsequent qualification tests or outdoor using. These results laid the foundation for studying the mechanical properties of front contact metallization for screen-printed crystalline silicon solar cells.This research was supported by the National Natural Science Foundation of China (No.61274050).西安交通大学硕士学位论文IVKEY WORDS: Solar cells; Ag-Si contact; Adhesion; ReliabilityTYPE OF THESIS: Application Research目 录V目 录1 绪论 .11.1 太阳电池的发展及其现状 .11.2 本文主要的研究工作 .41.2.1 选题背景 .41.2.2 研究内容及意义 .52 高效晶体硅太阳电池的工作原理及表征 .72.1 晶体硅太阳电池的工作原理 .72.2 太阳电池分类 .82.3 晶体硅太阳电池结构 .82.4 晶体硅太阳电池参数表征 .92.4.1 光电流 .92.4.2 光电压 .112.4.3 等效电路 .122.4.4 输出功率 .122.4.5 填充因子 .122.4.6 太阳电池效率 .123 高效晶体硅太阳电池银硅接触结构力学性能理论研究 力学模型的建立 .133.1 理论推导 .133.2 实验验证 .183.3 结果和讨论 .193.4 本章小结 .204 高效晶体硅太阳电池银硅接触结构力学性能实验研究 .214.1 试验用高效晶体硅太阳电池及组件制备 .214.1.1 硅片检测 .214.1.2 清洗制绒 .224.1.3 扩散制结 .234.1.4 刻蚀 .244.1.5 去磷硅玻璃（PSG） .244.1.6 等离子增强化学气相沉积（PECVD）制备减反膜