The recent success of perovskite solar cells is based on two solid pillars: the rapid progress of their power conversion efficiency and their flexibility in terms of optoelectrical properties and processing methods. That versatility makes these devices ideal candidates for multi-junction photovoltaics. We report an optically optimized double junction CH₃NH₃PbI₃–CH₃NH₃PbI₃ tandem solar cell where the matched short-circuit current is maximized while parasitic absorption is minimized. The use of an additive vacuum-deposition protocol allows us to reproduce calculated stack designs, which comprise several charge selective materials that ensure appropriate band alignment and charge recombination. This rationalized configuration yields an unprecedented open circuit voltage of 2.30 V. Furthermore, this tandem solar cell features efficiencies larger than 18%, higher than those of the individual sub-cells. Low photo-current values allow reducing the losses associated to the series resistance of transparent contacts, which opens the door to the realization of efficient large area modules.

中文翻译：

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高压真空沉积CH ₃ NH ₃ PbI ₃ –CH ₃ NH ₃ PbI ₃串联太阳能电池†

钙钛矿太阳能电池最近的成功基于两个坚实的支柱：功率转换效率的快速进步以及在光电性能和加工方法方面的灵活性。这种多功能性使这些器件成为多结光伏器件的理想候选者。我们报告了光学优化的双结CH ₃ NH ₃ PbI ₃ –CH ₃ NH ₃ PbI ₃串联太阳能电池，其中匹配的短路电流最大，而寄生吸收最小。附加真空沉积方案的使用使我们能够重现计算出的堆栈设计，其中包括几种电荷选择材料，可确保适当的能带对准和电荷重组。这种合理的配置可产生前所未有的2.30 V开路电压。此外，这种串联太阳能电池的效率高于18％，高于单个子电池的效率。低的光电流值可以减少与透明触点的串联电阻相关的损耗，这为实现高效的大面积模块打开了方便之门。