posted on 2024-02-12, 07:29authored byQinglong Zhu, Pin Lv, Yuxi Zhang, Yijie Wang, Gan Luo, Ziqi An, Min Hu, Kaiwen Hu, Wangnan Li, Feifei Yang, Bo Zhang, Zhiliang Ku, Yi-Bing Cheng, Jianfeng Lu
Lithium
bis(trifluoromethane) sulfonamide (LiTFSI) and oxygen-doped
organic semiconductors have been frequently used to achieve record
power conversion efficiencies of perovskite solar cells (PSCs). However,
this conventional doping process is time-consuming and leads to poor
device stability due to the incorporation of Li ions. Herein, aiming
to accelerate the doping process and remove the Li ions, we report
an alternative p-doping process by mixing a new small-molecule organic
semiconductor, N2,N2,N7,N7-tetrakis (4-methoxyphenyl)-9-(4-(octyloxy) phenyl)-9H carbazole-2,7-diamine (labeled OH44) and its preoxidized form OH44+(TFSI–). With this method, a champion efficiency
of 21.8% has been achieved for small-area PSCs, which is superior
to the state-of-the-art EH44 and comparable with LiTFSI and oxygen-doped spiro-OMeTAD. Moreover, the stability of OH44-based PSCs
is improved compared with those of EH44, maintaining more than 85%
of its initial efficiency after aging in an ambient condition without
encapsulation for 1000 h. In addition, we achieved efficiencies of
14.7 and 12.6% for the solar modules measured with a metal mask of
12.0 and 48.0 cm2, respectively, which demonstrated the
scalability of this method.