苏州大学李永舫团队报道了钙钛矿-有机串联太阳能电池的异构体二铵钝化。相关研究成果于2024年10月14日发表在国际知名学术期刊《自然》。

近年来，钙钛矿已被广泛应用于串联单片串联太阳能电池（TSCs）中，以克服单结太阳能电池的肖克利-奎塞尔极限。钙钛矿/有机TSCs，包括作为前电池的宽带隙（WBG）钙钛矿太阳能电池（pero-SC）和作为后电池的窄带隙有机太阳能电池（OSC），由于其良好的稳定性和潜在的高功率转换效率（PCE），引起了人们的关注。

然而，WBG pero-SC通常比常规pero-SC表现出更高的电压损失，这限制了TSCs的性能。主要障碍之一来自钙钛矿/C60界面的界面复合，开发有效的表面钝化策略以追求钙钛矿/有机TSCs的更高PCE非常重要。

该文中，研究人员开发了一种新的天然含有两种异构结构的表面钝化剂环己烷1,4-二碘化二铵（CyDAI₂），在己烷环的相同或相反侧有铵基团（分别表示为顺式CyDAI₂和反式CyDAI₂），这两种异构体表现出完全不同的表面相互作用行为。

顺式CyDAI₂钝化处理降低了带隙为1.88 eV的WBG pero SCs的准费米能级分裂（QFLS）-开路电压（Voc）失配，并将其Voc提高到1.36 V。结合顺式CyDAI₂处理的钙钛矿和带隙为1.24 eV的有机活性层，构建的单片钙钛矿/有机TSC的PCE为26.4%（认证为25.7%）。

附：英文原文

Title: Isomeric diammonium passivation for perovskite–organic tandem solar cells

Author: Jiang, Xin, Qin, Shucheng, Meng, Lei, He, Guorui, Zhang, Jinyuan, Wang, Yiyang, Zhu, Yiqiao, Zou, Tianwei, Gong, Yufei, Chen, Zekun, Sun, Guangpei, Liu, Minchao, Li, Xiaojun, Lang, Felix, Li, Yongfang

Issue&Volume: 2024-10-14

Abstract: In recent years, perovskite has been widely adopted in series-connected monolithic tandem solar cells (TSCs) to overcome the Shockley–Queisser limit of single-junction solar cells. Perovskite/organic TSCs, comprising a wide-bandgap (WBG) perovskite solar cell (pero-SC) as the front cell and a narrow-bandgap organic solar cell (OSC) as the rear cell, have recently drawn attention owing to the good stability and potential high power conversion efficiency (PCE)1,2,3,4. However, WBG pero-SCs usually exhibit higher voltage losses than regular pero-SCs, which limits the performance of TSCs5,6. One of the major obstacles comes from interfacial recombination at the perovskite/C60 interface, and it is important to develop effective surface passivation strategies to pursue higher PCE of perovskite/organic TSCs7. Here we exploit a new surface passivator cyclohexane 1,4-diammonium diiodide (CyDAI2), which naturally contains two isomeric structures with ammonium groups on the same or opposite sides of the hexane ring (denoted as cis-CyDAI2 and trans-CyDAI2, respectively), and the two isomers demonstrate completely different surface interaction behaviors. The cis-CyDAI2 passivation treatment reduces the Quasi–Fermi level splitting (QFLS)–open circuit voltage (Voc) mismatch of the WBG pero-SCs with a bandgap of 1.88 eV and enhanced its Voc to 1.36 V. Combining the cis-CyDAI2 treated perovskite and the organic active layer with a narrow-bandgap of 1.24 eV, the constructed monolithic perovskite/organic TSC demonstrates a PCE of 26.4% (certified as 25.7%).

DOI: 10.1038/s41586-024-08160-y

Source: https://www.nature.com/articles/s41586-024-08160-y