Reflection distributions of textured monocrystalline silicon: implications for silicon solar cells
Reflection distributions of textured monocrystalline silicon: implications for silicon solar cells
复制标题
DOI：
10.1002/pip.2186
复制
发表时间：
2013-08-01
影响因子：
6.7
通讯作者：
McIntosh, Keith R.
中科院分区：
文献类型：
--
作者：
Baker-Finch, Simeon C.;McIntosh, Keith R.
一个常见的误解是，碱性织构硅太阳能电池表面的特征是金字塔形且以{111}面为界。与观察扫描电子显微镜图像的典型方法相比，我们分析了各种金字塔纹理的反射分布，发现{111}面金字塔与此类表面上的特征的近似程度很差。我们得出的结论是，特征是带有八角形底座的小丘。此外，纹理的特征底角取决于蚀刻剂，并且比普遍接受的值54.74度更接近50-52度。对纹理表面的抗反射、光捕获、光生成和表面复合特性的分析应考虑到这种特征形态。底角对纹理表面的半球形反射率有很大影响，角度越大，反射率越低。当应用优化的抗反射涂层时，这种反射增强对器件性能的影响最小；与{111}面金字塔阵列相比，底角为50度的小丘形态导致典型电池中的光生电流减少0.2%。此外，随着底角减小，需要折射率越来越高的密封剂来驱动最初从电池表面反射的光在空气-玻璃界面处的内反射。鼓励开发可产生更高底角的纹理工艺。版权所有 (c) 2012 John Wiley & Sons, Ltd.
A common misconception is that alkaline textured silicon solar cell surfaces are characterised by features that are pyramidal and bounded by {111} planes. In preference to the typical approach of observing scanning electron microscope images, we analyse reflection distributions from various pyramidal textures and find that {111} faceted pyramids are a poor approximation to the features on such surfaces. We conclude that features are hillocks, with an octagonal base. Furthermore, the characteristic base angle of the texture depends on the etchant and is closer to 50-52 degrees than the commonly accepted value of 54.74 degrees. Analyses of antireflection, light trapping, photogeneration and surface recombination properties of textured surfaces should take this feature morphology into account. The base angle has a strong influence on the hemispherical reflectance of the textured surface, with higher angles resulting in reduced reflectance. The influence of this reflection enhancement upon device performance is smallest when an optimised antireflection coating is applied; compared with an array of {111} faceted pyramids, a hillock morphology with 50 degrees base angle results in a 0.2% reduction in photogenerated current in a typical cell. Additionally, as base angle is reduced, an encapsulant of increasingly higher refractive index is required to drive internal reflection at the air-glass interface of light initially reflected from the cell surface. The development of texturing processes resulting in higher base angles is encouraged. Copyright (c) 2012 John Wiley & Sons, Ltd.