Carrier lifetimes of >1 μs in Sn-Pb perovskites enable efficient all-perovskite tandem solar cells
Carrier lifetimes of >1 μs in Sn-Pb perovskites enable efficient all-perovskite tandem solar cells
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DOI：
10.1126/science.aav7911
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发表时间：
2019-05-03
期刊：
影响因子：
56.9
通讯作者：
Zhu, Kai
中科院分区：
文献类型：
--
作者：
Tong, Jinhui;Song, Zhaoning;Zhu, Kai
全钙钛矿基多晶薄膜串联太阳能电池的效率有可能达到30%。然而，由于缺乏高效、低带隙锡-铅（Sn-Pb）混合钙钛矿太阳能电池（PSCs），全钙钛矿串联器件的性能受到限制。研究发现，硫氰酸胍（GuaSCN）的加入显著改善了Sn-Pb混合低带隙（约1.25电子伏）钙钛矿薄膜的结构和光电性能。薄膜的缺陷密度降低了10倍，导致载流子寿命大于1微秒，扩散长度为2.5微米。这些改进的性能使我们能够演示>20%效率的低带隙psc。当与宽禁带PSCs结合时，我们获得了25%效率的四端和23.1%效率的二端全钙钛矿基多晶薄膜串联太阳能电池。
All-perovskite-based polycrystalline thin-film tandem solar cells have the potential to deliver efficiencies of >30%. However, the performance of all-perovskite-based tandem devices has been limited by the lack of high-efficiency, low-band gap tin-lead (Sn-Pb) mixed-perovskite solar cells (PSCs). We found that the addition of guanidinium thiocyanate (GuaSCN) resulted in marked improvements in the structural and optoelectronic properties of Sn-Pb mixed, low-band gap (similar to 1.25 electron volt) perovskite films. The films have defect densities that are lower by a factor of 10, leading to carrier lifetimes of greater than 1 microsecond and diffusion lengths of 2.5 micrometers. These improved properties enable our demonstration of >20% efficient low-band gap PSCs. When combined with wider-band gap PSCs, we achieve 25% efficient four-terminal and 23.1% efficient two-terminal all-perovskite-based polycrystalline thin-film tandem solar cells.