柔性太阳能电池的结构优化设计与疲劳分析

发布时间：2018-04-19 01:23

本文选题：柔性太阳能电池 + 结构化基体　；参考：《西南交通大学》2017年硕士论文

【摘要】：柔性电子技术是一种将电子元件集成在柔性基体上,从而使刚性的电子元件有了较大延展性的新型技术,在近十年来得到了迅速的发展。柔性太阳能电池就利用此技术,将脆性的GaAs电池模块粘贴在超弹性材料PDMS上,使整个薄膜电池结构的延展性得到了增加。为了进一步增加电池的延展性,并且在不显著增加薄膜电池总体厚度的情况下,本文提出了一种新的设计方案,在"单一岛体"型柔性太阳能电池基础之上,将基体的基底与岛体之间增加一个方形立柱来隔离基底的变形,使基体形成了"基底-立柱-岛体"的结构,相当于一个"复合岛体"结构。在此结构中,立柱的宽度、厚度以及岛体厚度对柔性太阳能电池的延展性有显著影响。应用有限元方法发现立柱的宽度对界面力和GaAs电池应变的影响特别显著,且立柱宽度小于300μm时基底以上的结构会因立柱失稳而倾斜。另外,立柱与岛体的厚度对界面力和GaAs电池应变的影响程度比立柱的宽度影响要小很多。基底的厚度的影响相比于立柱的宽度来说可以忽略不计。最后,保护膜厚度越大对GaAs电池和界面力的影响都会增大。在实际情况中,柔性太阳能电池常常会受到外力的反复加载,很容易造成软基底和硬的GaAs电池之间的界面发生脱粘,从而导致整个结构失效。而此结构的材料间刚度差异非常大,其界面破坏机理非常复杂,且至今还没有关于柔性太阳能电池界面疲劳方面的研究,因此将重心放在研究"单一岛体"与"复合岛体"型太阳能电池在拉伸和弯曲循环载荷下界面破坏的差异性上。考虑了包括剪切和拉伸在内的内聚力模型,并通过采用内聚力模型对界面破坏进行数值分析。发现"单一岛体"型柔性太阳能电池界面破坏速率比相同循环载荷下的"复合岛体"型柔性太阳能电池要快得多。而且,两种设计的界面破坏的起始位置显著不同。例如,在拉伸的循环加载下,"单一岛体"型柔性太阳能电池界面破坏从四个角开始,然后向界面中心逐渐演化。然而,"复合岛体"型柔性太阳能电池界面破坏大致从方形立柱的四个角上的垂直投影开始。此外,循环载荷越大,"单一岛体"型柔性太阳能电池的界面破坏速率越快。另外,两种设计都可以忽略导线的影响。最后,所提出的"复合岛体"设计可延展性能比"单一岛体"设计显着提高了,变形隔离效果更好。如果电池界面破坏是主要破坏方式,那么"复合岛体"设计的疲劳寿命将会更长。因此,新设计的"复合岛体""型柔性太阳能电池疲劳寿命更长。所有这些数值分析结果将有助于指导太阳能电池基体的设计。
[Abstract]:Flexible electronic technology is a new technology which integrates electronic components on flexible matrix and makes rigid electronic components more extensible. It has been developed rapidly in the last ten years.Flexible solar cells use this technology to attach brittle GaAs modules to super-elastic material PDMS, which increases the ductility of the whole thin film cell structure.In order to further increase the ductility of the cell, and without significantly increasing the total thickness of the thin film cell, this paper presents a new design scheme, which is based on the "single island" flexible solar cell.A square column is added between the substrate and the island body to isolate the deformation of the substrate, which makes the matrix form a "base-pillar" structure, which is equivalent to a "composite island body" structure.In this structure, the width, thickness and island thickness of the column have a significant effect on the ductility of flexible solar cells.The finite element method is used to find that the width of the column has a significant effect on the interface force and the strain of the GaAs battery, and that the structure above the base of the column is inclined because of the instability of the column when the width of the column is less than 300 渭 m.In addition, the influence of the thickness of the column and the island body on the interface force and the strain of GaAs battery is much less than that on the width of the column.The effect of the thickness of the base is negligible relative to the width of the column.Finally, the effect of the thickness of the protective film on the GaAs cell and the interface force will increase.In practice, flexible solar cells are often subjected to repeated external loading, which can easily cause the interface between the soft substrate and the hard GaAs cells to be debonded, resulting in the failure of the whole structure.However, the stiffness of the structure is very different, the mechanism of interface failure is very complex, and there is no research on interface fatigue of flexible solar cells.Therefore, the center of gravity is focused on the study of the difference of interface failure between "single island" and "composite island" solar cells under tensile and bending cyclic loading.The cohesive force model including shear and tensile is considered, and the interface failure is analyzed numerically by using cohesion model.It is found that the interface failure rate of the "single island" flexible solar cell is much faster than that of the "composite island" flexible solar cell under the same cyclic load.Moreover, the initial location of the interface failure is significantly different between the two designs.For example, under the cyclic loading of tension, the interface failure of the "single island" flexible solar cell starts at four angles and then evolves to the interface center.However, the interface failure of the composite island type flexible solar cell begins with the vertical projection of the four angles of the square column.In addition, the larger the cyclic load, the faster the interface failure rate of single island flexible solar cell is.In addition, both designs can ignore the influence of wires.Finally the ductility of the proposed "composite island body" design is significantly improved than that of the "single island body" design and the deformation isolation effect is better than that of the "single island body" design.If the battery interface failure is the main failure mode, the fatigue life of the composite island body will be longer.Therefore, the newly designed "composite island" type flexible solar cells have longer fatigue life.All these numerical results will be helpful to guide the design of solar cell matrix.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM914.4

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