Metal-halide perovskite-based tandem solar cells show great promise for overcoming the Shockley–Queisser single-junction efficiency limit via low-cost tandem structures, but so far, they employ conventional bottom-cell materials that require stringent processing conditions. Meanwhile, difficulty in achieving low-bandgap (<1.1 eV) perovskites limits all-perovskite tandem cell development. Here we propose a tandem cell design based on a halide perovskite top cell and a chalcogenide colloidal quantum dot (CQD) bottom cell, where both materials provide bandgap tunability and solution processability. A theoretical efficiency of 43% is calculated for tandem-cell bandgap combinations of 1.55 (perovskite) and 1.0 eV (CQDs) under 1-sun illumination. We highlight that intersubcell radiative coupling contributes significantly (>11% absolute gain) to the ultimate efficiency via photon recycling. We report an initial experimental demonstration of a solution-processed monolithic perovskite/CQD tandem solar cell, showing evidence for subcell voltage addition. We model that a power conversion efficiency of 29.7% is possible by combining state-of-the-art perovskite and CQD solar cells.

中文翻译：

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钙钛矿/胶体量子点串联太阳能电池：理论建模和整体结构。

基于金属卤化物钙钛矿的串联太阳能电池显示出通过低成本串联结构克服肖克利-奎塞尔单结效率极限的巨大希望，但到目前为止，它们采用了要求严格加工条件的常规底部电池材料。同时，难以实现低带隙（<1.1 eV）的钙钛矿限制了全钙钛矿串联细胞的发展。在这里，我们提出了基于卤化物钙钛矿顶部电池和硫族化物胶体量子点（CQD）底部电池的串联电池设计，其中两种材料都提供了带隙可调性和溶液可加工性。在1个太阳光照射下，串联电池带隙组合为1.55（钙钛矿）和1.0 eV（CQD）的理论效率为43％。我们着重指出，亚细胞间辐射耦合的作用很大（> 11％的绝对增益）通过光子回收达到最终效率。我们报告了溶液处理的整体钙钛矿/ CQD串联太阳能电池的初步实验演示，显示了添加子电池电压的证据。我们建模通过将最先进的钙钛矿和CQD太阳能电池相结合，可以实现29.7％的功率转换效率。