We develop an analytical model for the photocurrent of organic solar cells based on carrier drift and including second-order charge recombination, in which the figure of merit ${\theta }_o$ naturally appears. This approach provides expressions for the fill-factor–${\theta }_o$ and α-${\theta }_o$ relations, where α is the exponent of the function of the short-circuit current versus light intensity ($J_{\mathrm{SC}}$ ∝ $I^{\alpha }$). A correlation between the reduction factor of Langevin recombination and the dissociation probability of charge transfer states (P) is also discussed. Photocurrent curves of a polymer device obtained at different temperatures (100–300 K) are fitted by the model, whose fitting parameters are in agreement with the literature.

中文翻译：

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有机太阳能电池中光电流的分析模型与包括二阶复合在内的电荷输运品质因数的关系

我们基于载流子漂移并包括二阶电荷复合，建立了有机太阳能电池光电流的分析模型，其中的品质因数 ${\theta }_{Ø}$自然地出现。这种方法提供了填充因子的表达式–${\theta }_{Ø}$和α -${\theta }_{Ø}$关系，其中α是短路电流与光强度的函数的指数（${Ĵ}_{\mathrm{SC}}$ ∝ ${\mathrm{一世}}^{\alpha }$）。还讨论了兰格文重组的减少因子与电荷转移态（P）的解离概率之间的相关性。该模型拟合了在不同温度（100–300 K）下获得的聚合物器件的光电流曲线，其拟合参数与文献一致。