The thermodynamic limit of photovoltaic efficiency for a single-junction solar cell can be readily predicted using the bandgap of the active light absorbing material. Such an approach overlooks the energy loss due to non-radiative electron-hole processes. We propose a practical ab initio procedure to determine the maximum efficiency of a thin-film solar cell that takes into account both radiative and non-radiative recombination. The required input includes the frequency-dependent optical absorption coefficient, as well as the capture cross sections and equilibrium populations of point defects. For kesterite-structured Cu₂ZnSnS₄, the radiative limit is reached for a film thickness of around 2.6 μm, where the efficiency gain due to light absorption is counterbalanced by losses due to the increase in recombination current.

中文翻译：

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单pn结锌黄锡矿太阳能电池光伏效率详细平衡极限的从头算计算

使用活性光吸收材料的带隙可以很容易地预测单结太阳能电池光伏效率的热力学极限。这种方法忽略了由于非辐射电子空穴过程造成的能量损失。我们提出了一种实用的ab initio程序来确定薄膜太阳能电池的最大效率，该程序同时考虑了辐射复合和非辐射复合。所需的输入包括与频率相关的光吸收系数，以及点缺陷的捕获截面和平衡种群。对于黄铜矿结构的 Cu ₂ ZnSnS ₄，达到辐射极限时膜厚约为 2.6  μm，其中由光吸收引起的效率增益被由于复合电流增加引起的损失所抵消。