Xin Yufei, Liu Hang, Dong Xiyue, Xiao Zheng, Wang Rui, Gao Yuping, Zou Yu, Kan Bin, Wan Xiangjian, Liu Yongsheng, Chen Yongsheng
The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer Materials, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin 300350, China.
J Am Chem Soc. 2024 Feb 7;146(5):3363-3372. doi: 10.1021/jacs.3c12605. Epub 2024 Jan 24.
Inverted organic solar cells (OSCs) have attracted much attention because of their outstanding stability, with zinc oxide (ZnO) being commonly used as the electron transport layer (ETL). However, both surface defects and the photocatalytic effect of ZnO could lead to serious photodegradation of acceptor materials. This, in turn, hampers the improvement of the efficiency and stability in OSCs. Herein, we developed a multiarmed aromatic ammonium salt, namely, benzene-1,3,5-triyltrimethanaminium bromide (PhTMABr), for modifying ZnO. This compound possesses mild weak acidity aimed at removing the residual amines present within ZnO film. In addition, the PhTMABr could also passivate surface defects of ZnO through multiple hydrogen-bonding interactions between its terminal amino groups and the oxygen anion of ZnO, leading to a better interface contact, which effectively enhances charge transport. As a result, an efficiency of 18.75% was achieved based on the modified ETL compared to the bare ZnO (PCE = 17.34%). The devices utilizing the modified ZnO retained 87% and 90% of their initial PCE after thermal stress aging at 65 °C for 1500 h and continuous 1-sun illumination with maximum power point (MPP) tracking for 1780 h, respectively. Importantly, the extrapolated T lifetime with MPP tracking exceeds 10 000 h. The new class of materials employed in this work to modify the ZnO ETL should pave the way for enhancing the efficiency and stability of OSCs, potentially advancing their commercialization process.
倒置有机太阳能电池（OSCs）因其出色的稳定性而备受关注，氧化锌（ZnO）通常用作电子传输层（ETL）。然而，ZnO的表面缺陷和光催化效应都可能导致受体材料严重的光降解。这反过来又阻碍了OSCs中效率和稳定性的提高。在此，我们开发了一种多臂芳香铵盐，即苯-1,3,5-三基三甲铵溴化物（PhTMABr），用于修饰ZnO。该化合物具有温和的弱酸性，旨在去除ZnO薄膜中存在的残留胺。此外，PhTMABr还可以通过其末端氨基与ZnO的氧阴离子之间的多重氢键相互作用来钝化ZnO的表面缺陷，从而实现更好的界面接触，有效增强电荷传输。结果，基于修饰后的ETL实现了18.75%的效率，相比之下，裸ZnO的效率为17.34%。在65°C下热应力老化1500小时以及在最大功率点（MPP）跟踪下连续1太阳光照1780小时后，使用修饰后的ZnO的器件分别保留了其初始PCE的87%和90%。重要的是，在MPP跟踪下外推的T寿命超过10000小时。这项工作中用于修饰ZnO ETL的新型材料应为提高OSCs的效率和稳定性铺平道路，有可能推动其商业化进程。
