In order to identify the cause of the difference between actual efficiency and the theoretical limit in state‐of‐the‐art triple‐junction solar cells, we investigate the internal luminescence efficiency in the depletion region ( ). The average internal luminescence efficiency of the whole subcell volume ( ) is obtained experimentally, and the is deduced by numerical calculations using rate equations. We find that and agree well in the low‐recombination current regime including the maximum power point. This indicates that the non‐radiative recombination loss at the maximum power point strongly depends on the recombination in the depletion region. Furthermore, we determine the actual Shockley–Read–Hall recombination coefficient in the depletion region, A^dep, which is proportional to the effective density of recombination centers. Our analysis reveals the target values of A^dep required for realizing conversion efficiencies that are within 1% of the internal radiative limit. The analysis also clarifies the extent of reduction of the effective density of recombination centers (in the depletion region) that is required to realize a given target efficiency.

中文翻译：

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最新三结太阳能电池中Shockley-Read-Hall重组率的实际目标值，可实现转换效率在内部辐射极限的1％以内

为了查明最先进的三结太阳能电池的实际效率和理论极限之间存在差异的原因，我们研究了耗尽区的内部发光效率（ ）。通过实验获得整个子电池体积（）的平均内部发光效率 ，并通过使用速率方程的数值计算推导得出。我们发现，与低重组目前的制度，包括最大功率点吻合。这表明最大功率点的非辐射重组损失在很大程度上取决于耗尽区的重组。此外，我们确定了耗尽区A中的实际Shockley-Read-Hall重组系数^dep，它与重组中心的有效密度成正比。我们的分析揭示了实现转换效率在内部辐射极限的1％以内所需的A ^dep的目标值。分析还阐明了实现给定目标效率所需的重组中心（耗尽区）有效密度降低的程度。