Singlet exciton fission allows for the generation of two triplet excitons for each photon absorbed within an organic semiconductor. Efficient harvesting of these triplets could allow for the Shockley–Queisser limit on the power conversion efficiency of single-junction photovoltaics to be broken. Here, we show that singlet fission molecules bound directly to PbS quantum dots as ligands can undergo singlet fission with near unity efficiency and can transfer triplets sequentially into the PbS with near unity efficiency. Within the PbS, the excitations recombine, giving rise of the emission of photons. This allows for the doubling of the quantum dot photoluminescence quantum efficiency when photons are absorbed by the singlet fission ligand, as compared to when directly absorbed in the quantum dot. Our approach demonstrates that it is possible to convert the exciton multiplication process of singlet fission into a photon multiplication process and provides a new path to harness singlet fission with photovoltaics.

中文翻译：

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TIPS-四氢呋喃羧酸配体中的单重态裂变和三重态转移到PbS量子点。

单重态激子裂变可为有机半导体中吸收的每个光子产生两个三重态激子。这些三胞胎的有效收获可以打破肖克利-奎塞尔对单结光伏电池功率转换效率的限制。在这里，我们显示作为配体直接结合到PbS量子点的单重态裂变分子可以以接近统一的效率经历单重态裂变，并且可以以接近统一的效率将三重态依次转移到PbS中。在PbS中，激发复合，从而产生光子发射。与直接吸收在量子点中相比，当光子被单线态裂变配体吸收时，量子点的光致发光量子效率加倍。