Zhang Caiyi, Kong Weiyu, Wu Tianhao, Lin Xuesong, Wu Yongzhen, Nakazaki Jotaro, Segawa Hiroshi, Yang Xudong, Zhang Yiqiang, Wang Yanbo, Han Liyuan
State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China.
Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.
ACS Appl Mater Interfaces. 2021 Sep 22;13(37):44321-44328. doi: 10.1021/acsami.1c11683. Epub 2021 Sep 8.
Inverted perovskite solar cells (IPSCs) attract growing interest because of their simple configuration, reliable stability, and compatibility with tandem applications. However, the power conversion efficiency (PCE) of IPSCs still lags behind their regular counterparts, mainly due to the more serious nonradiative loss. Here, we design three donor-π-acceptor (D-π-A) dipoles with various dipole moments to introduce extra electric fields at the interface of perovskites and electron transport materials via the binding between the carboxylate end group and under-coordinated divalent Pb. The chemical binding reduces the recombination centers, while the superposition of the built-in electric field facilitates the electron collection and the hole blocking. As a result, the nonradiative loss is diminished as the dipole moments of D-π-A dipoles increase, which contributes to a PCE of 21.4% with enhancement in both the open-circuit voltage and fill factor. The stability for an unencapsulated device is also improved due to the hydrophobic property of D-π-A dipoles.
倒置钙钛矿太阳能电池（IPSCs）因其结构简单、稳定性可靠以及与串联应用的兼容性而受到越来越多的关注。然而，IPSCs的功率转换效率（PCE）仍落后于其常规同类产品，主要原因是其非辐射损失更为严重。在此，我们设计了三种具有不同偶极矩的供体-π-受体（D-π-A）偶极子，通过羧酸酯端基与低配位二价铅之间的结合，在钙钛矿和电子传输材料的界面处引入额外的电场。这种化学键合减少了复合中心，而内建电场的叠加促进了电子收集和空穴阻挡。结果，随着D-π-A偶极子偶极矩的增加，非辐射损失减小，这有助于实现21.4%的PCE，同时开路电压和填充因子均有所提高。由于D-π-A偶极子的疏水性，未封装器件的稳定性也得到了改善。
