Optical properties of silicon light trapping structures for photovoltaics
Optical properties of silicon light trapping structures for photovoltaics
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DOI：
10.1016/j.solmat.2010.07.020
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发表时间：
2010-12
影响因子：
6.9
通讯作者：
V. Iyengar;B. K. Nayak;M. Gupta
中科院分区：
文献类型：
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作者：
V. Iyengar;B. K. Nayak;M. Gupta
光捕获结构对抑制反射损失和提高转换效率至关重要。对于硅片（Si）太阳能电池，这通常是通过化学纹理和应用抗反射涂层来实现的。这样的表面仍然显示出显著的反射损耗，约为10%。因此，为了进一步减少反射，需要探索在较宽的太阳光谱和角度范围内有效的新捕光方法。在本文中，我们探索了一种超快激光纹理化方法，成功地在较宽的光谱和角度范围内将反射率降低到5%以下，更重要的是，它适用于晶体、多晶、薄膜硅等材料。用包括散射在内的全反射作为波长和入射角的函数，评价了在六氟化硫（SF6）气体环境中产生的超快激光织构硅表面的光学特性。光学结果进一步与其他纹理方案进行了比较。研究了超快织构法对硅带隙的改性。最后，比较了由超快激光纹理表面、化学纹理表面、多孔硅表面和蚀刻硅表面制成的太阳能电池的光电参数，以了解表面纹理对光电器件性能的影响。
Light trapping structures in photovoltaics are essential to suppress reflection losses and increase conversion efficiency. For wafer silicon (Si) solar cells, this is commonly achieved by chemical texturing and the application of an antireflection coating. Such surfaces still show significant reflection losses that are ∼10%. Hence, for further reduction in reflection, new methods for light trapping need to be explored, which are effective for a broad solar spectral and angular range. In this paper, we explore an ultrafast laser texturing method that successfully reduces the reflection below 5% over a broad spectral and angular range and more importantly, is applicable to crystalline, multi-crystalline, thin film silicon and other materials. The optical properties of ultrafast laser textured silicon surfaces produced in a sulfur hexafluoride (SF6) gas ambient are evaluated by total reflection including scattering as a function of wavelength and angle of incidence. The optical results are further compared with other texturing schemes. This study also investigates the silicon bandgap modification induced by ultrafast texturing method. Finally, a comparison is made for the photovoltaic parameters of solar cells made of ultrafast laser textured surfaces, chemically textured surfaces, porous silicon surfaces, and etched silicon surfaces that result in nanowires for light trapping to understand impact of surface texturing on photovoltaic device performance.