CsPbIBr2钙钛矿太阳能电池中通过氧气诱导Spiro-OMeTAD快速氧化

Spiro-OMeTAD是钙钛矿型太阳能电池中应用最广泛的空穴传输材料,它本身的空穴传输率很低,需要氧化之后才能满足高效率太阳能电池器件的要求。然而,Spiro-OMeTAD在空气中的氧化时间较长,同时空气中的水分会造成器件效率的下降以及器件质量不稳定等不良后果。基于此,我们通过一步法制备CsPbIBr₂无机钙钛矿太阳能电池,并将旋涂了Spiro-OMeTAD层的器件放在纯氧气中氧化,避免因水分导致的钙钛矿层分解。实验结果表明,氧气氧化后的器件最高效率为7.19%,高于空气中氧化的器件达到的最高效率6.29%,并且氧气氧化可以将Spiro-OMeTAD的氧化时间从18小时缩短到5小时。我们采用一系列电化学表征方法探讨了不同氧化条件下电池器件的性能差异.结果显示,纯氧气氧化Spiro-OMeTAD可以有效减低载流子复合,提高电荷传输。此外,我们采集了多个样本统计分析,发现采用氧气氧化的器件平均效率更高,器件质量更稳定,具有更好的可重复性。这种快速稳定的氧化方法为钙钛矿型太阳能电池的商业化开发提供了有效的思路。

Oxygen-Exposure Induced Rapid Oxidation of Spiro-OMeTAD in CsPbIBr2 Perovskite Solar Cells

2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene(Spiro-OMeTAD)is the most widely used hole transport material in perovskite solar cells(PSCs).However,its oxidation in the air takes a long time and results in the attack of perovskite by water.In this regard,we performed the oxidation process of Spiro-OMeTAD in oxygen,where perovskite can be pro-tected from water,guaranteeing the integrity of perovskite.It was demonstrated that the champion Spiro-OMeTAD based CsPbIBr2 PSCs after oxygen oxidation achieved a 7.19％power conversion efficiency(PCE),showing a higher PCE than 6.29％of the cham-pion device oxidized in air.A series of electrochemical characterization methods were applied to investigate the performances of the different cell devices under different oxidation conditions.It was revealed that the oxygen oxidation enabled to enhance the hole conductivity of Spiro-OMeTAD,reduce the charge recombination and improve the charge transfer efficiency in PSCs.Moreover,the device with oxygen oxidation had a higher average efficiency and greater stability.This method makes the devices have better repeatability,which provides a reliable idea for the commercial development of PSCs.