Impact of silicon wafer thickness on photovoltaic performance of crystalline silicon heterojunction solar cells
Impact of silicon wafer thickness on photovoltaic performance of crystalline silicon heterojunction solar cells
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硅片厚度对晶硅异质结太阳能电池光伏性能的影响
DOI：
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发表时间：
2018
影响因子：
1.5
通讯作者：
K. Matsubara
中科院分区：
文献类型：
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作者：
H. Sai;Hiroshi Umishio;T. Matsui;S. Nunomura;T. Kawatsu;H. Takato;K. Matsubara
从光学和电学角度研究了硅片厚度对氢化非晶硅/晶体硅（a-Si：H/c-Si）异质结太阳电池光伏性能的影响。不同厚度的c-Si晶片的光学表征表明，一个现实的光捕获方案，即，具有介电层和背反射器的纹理化Si晶片实现了有效的准朗伯光吸收增强，即使对于非常薄的晶片。这表明，高的光电流密度是可以实现的，通过使用现实的光捕获方案，假设寄生吸收损失最小化。采用本征/掺杂非晶硅薄膜钝化的薄c-Si晶片研究了薄c-Si电池的开路电压（VOC）和填充因子（FF）。实验证实，随着晶片厚度减小到30 µm，隐含的VOC稳定增加，而隐含的FF对厚度的依赖性很弱。作为光吸收和隐含VOC之间的权衡的结果，对于宽范围的晶片厚度预期高隐含效率。在厚度低于60 µm的a-Si：H/c-Si异质结电池中，也通过实验证实了通过减薄晶片而增加的VOC，导致21.0%的转换效率。
The impact of Si wafer thickness on the photovoltaic performance of hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si) heterojunction solar cells was examined from the optical and electrical points of view. Optical characterization of c-Si wafers of various thicknesses showed that a realistic light-trapping scheme, i.e., pyramidally textured Si wafers with a dielectric antireflection coating and a back reflector, realizes an efficient quasi-Lambertian light absorption enhancement, even for very thin wafers. This indicates that high photocurrent densities are achievable by using the realistic light-trapping scheme, assuming that the parasitic absorption loss is minimized. The potentials of open-circuit voltage (VOC) and the fill factor (FF) of thin c-Si cells were investigated using thin c-Si wafers passivated with intrinsic/doped amorphous silicon film stacks. It was experimentally confirmed that the implied VOC increases steadily with decreasing wafer thickness down to 30 µm, while the implied FF weakly depends on the thickness. As a result of the trade-off between light absorption and implied VOC, a high implied efficiency is expected for a wide range of wafer thicknesses. The VOC increase by thinning the wafer was also experimentally confirmed in an a-Si:H/c-Si heterojunction cell with a thickness below 60 µm, resulting in a conversion efficiency of 21.0%.