Zhang Jiyao, Hu Hang, Zhang Yong, Liang Zheng, Zhu Peide, Li Zhitong, Wang Deng, Chen Jiabang, Zeng Jie, Jiang Zhengyan, Wu Jiawen, Zhang Luozheng, Hu Bihua, Pan Xu, Wang Xingzhu, Xu Baomin
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Key University Laboratory of Highly Efficient Utilization of Solar Energy and Sustainable Development of Guangdong, Southern University of Science and Technology, Shenzhen 518055, China.
ACS Appl Mater Interfaces. 2023 Mar 29;15(12):15321-15331. doi: 10.1021/acsami.2c20915. Epub 2023 Feb 28.
Post-treatment has been recognized as one of the effective methods for passivating the underlying defects in perovskite solar cells (PSCs), but little attention has been paid to how to pick suitable passivation agents with diverse isomers for efficient PSCs, particularly for the tin-lead (Sn-Pb) mixed PSCs. Here, we introduce the dependence of the power conversion efficiency (PCE) on a dipole moment for surface passivator screening, in which we chose three trifluoromethyl-phenylethylamine hydroiodide (CF-PEAI) isomers as surface-treatment materials for hole-transport-layer-free (HTL-free) Sn-Pb mixed PSCs. The different positions of the -CF group for the CF-PEAI isomer result in different dipole moments, which influences the interaction between CF-PEAI and lead iodide. The para position CF with the highest dipole moment exhibits a higher PCE than the ortho-position with a lower dipole moment, which is attributed to the large dipole moment on the surface that could tune the surface polarity from p-type to n-type, facilitating electron charge transport in the HTL-free Sn-Pb mixed PSCs. An ultrathin 2D layer is formed on the perovskite surface to passivate the surface defects, which is responsible for the enhancement of the PCE and stability of the PSCs. As a result, the open-circuit voltage () of the device is improved from 0.775 to 0.824 V, yielding a champion PCE of 20.17%, which is one of the highest PCEs among the reported HTL-free Sn-Pb mixed PSCs. The device also shows improved stability with remaining 75% of its initial PCEs after storage in N for 700 h.
后处理已被公认为钝化钙钛矿太阳能电池（PSC）潜在缺陷的有效方法之一，但对于如何选择具有不同异构体的合适钝化剂以实现高效PSC，尤其是锡铅（Sn-Pb）混合PSC，却很少受到关注。在此，我们介绍了功率转换效率（PCE）对用于表面钝化剂筛选的偶极矩的依赖性，其中我们选择了三种三氟甲基苯乙胺氢碘化物（CF-PEAI）异构体作为无空穴传输层（HTL-free）Sn-Pb混合PSC的表面处理材料。CF-PEAI异构体中-CF基团的不同位置导致不同的偶极矩，这影响了CF-PEAI与碘化铅之间的相互作用。偶极矩最高的对位CF表现出比偶极矩较低的邻位更高的PCE，这归因于表面上的大偶极矩可以将表面极性从p型调节为n型，促进无HTL的Sn-Pb混合PSC中的电子电荷传输。在钙钛矿表面形成超薄二维层以钝化表面缺陷，这是PSC的PCE和稳定性提高的原因。结果，器件的开路电压从0.775 V提高到0.824 V，获得了20.17%的最佳PCE，这是报道的无HTL的Sn-Pb混合PSC中最高的PCE之一。该器件还显示出改善的稳定性，在N2中储存700小时后仍保留其初始PCE的75%。
