Perovskite-polymer composite cross-linker approach for highly-stable and efficient perovskite solar cells
Perovskite-polymer composite cross-linker approach for highly-stable and efficient perovskite solar cells
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DOI：
10.1038/s41467-019-08455-z
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发表时间：
2019-01-31
影响因子：
16.6
通讯作者：
Yang, Yang
中科院分区：
文献类型：
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作者：
Han, Tae-Hee;Lee, Jin-Wook;Yang, Yang
多晶钙钛矿中的晶界的操纵对于太阳能电池的光电性质和环境稳定性两者都是重要的考虑因素，因为钙钛矿膜的溶液处理不可避免地在晶界处引入许多缺陷。虽然小分子添加剂已被证明是有效的缺陷钝化剂，但它们的高挥发性和扩散性不能使钙钛矿膜对恶劣环境足够坚固。在这里，我们建议有效的分子设计规则，考虑他们的分子结构。由此，我们引入了一种使用长链聚合物形成大分子中间相的策略，这导致了聚合物-钙钛矿复合交联剂的形成。交联剂起到桥接钙钛矿晶粒的作用，使晶粒间的电去耦最小化，并产生优异的对水分、光和热的环境稳定性，这是小分子缺陷钝化剂所不能达到的。因此，所有的光伏参数都显着提高了太阳能电池和设备也表现出优异的稳定性。
Manipulation of grain boundaries in polycrystalline perovskite is an essential consideration for both the optoelectronic properties and environmental stability of solar cells as the solution-processing of perovskite films inevitably introduces many defects at grain boundaries. Though small molecule-based additives have proven to be effective defect passivating agents, their high volatility and diffusivity cannot render perovskite films robust enough against harsh environments. Here we suggest design rules for effective molecules by considering their molecular structure. From these, we introduce a strategy to form macromolecular intermediate phases using long chain polymers, which leads to the formation of a polymer-perovskite composite cross-linker. The cross-linker functions to bridge the perovskite grains, minimizing grain-to-grain electrical decoupling and yielding excellent environmental stability against moisture, light, and heat, which has not been attainable with small molecule defect passivating agents. Consequently, all photovoltaic parameters are significantly enhanced in the solar cells and the devices also show excellent stability.