Present practice to avoid harmful effects of UV light on dye solar cells (DSC) is to use a UV filter. However, we show here that a standard 400 nm UV cutoff filter offers inadequate protection from UV‐induced degradation. DSCs that were exposed to only visible light by LED lamps maintained 100% of their initial efficiency after 3000 hours of exposure, whereas the efficiency of DSCs subjected to full light spectrum (Xenon arc lamp) with an efficient UV filter dropped down to 10% of their initial performance already after 1500 hours. Optical analysis of the UV filter confirmed that the amount of light transmitted below 400 nm was negligible. These observations indicate that (a) DSCs can be very sensitive to even minor amount of UV and (b) eliminating the effects of UV light on DSC stability cannot easily be avoided by a UV filter on top of the cell. A detailed analysis of the degradation mechanisms revealed that the culprit to loss of performance was accelerated loss of charge carriers in the electrolyte of the DSCs—a typical symptom of UV exposure. These results suggest that commonly used stability tests under LED illumination are insufficient in predicting the lifetime of DSCs in outdoor conditions. Instead, for such purpose, we recommend solar cell stability to be tested with a full light spectrum and with a suitable UV filter.

中文翻译：

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染料太阳能电池对紫外线引起的降解极为敏感

为了避免紫外线对染料太阳能电池（DSC）的有害影响，目前的做法是使用紫外线过滤器。但是，我们在这里表明，标准的400 nm紫外线截止滤光片不能提供足够的保护，防止紫外线引起的降解。通过LED灯仅暴露于可见光的DSC在暴露3000小时后仍保持其初始效率的100％，而在全光谱（氙弧灯）下使用高效的UV滤光片的DSC的效率下降到了10％。 1500小时后，它们的初始性能已经开始。紫外线滤光片的光学分析证实，在400 nm以下透射的光量可以忽略不计。这些观察结果表明，（a）DSC对极少量的紫外线可能非常敏感，并且（b）消除紫外线对DSC稳定性的影响很难通过电池顶部的紫外线过滤器来避免。对降解机理的详细分析表明，性能下降的根源是DSC电解质中电荷载流子的加速损耗，这是紫外线暴露的典型症状。这些结果表明，在LED照明下常用的稳定性测试不足以预测DSC在室外条件下的使用寿命。相反，出于此目的，我们建议在全光谱和合适的紫外线滤光片下测试太阳能电池的稳定性。