Iodonium Initiators: Paving the Air-free Oxidation of Spiro-OMeTAD for Efficient and Stable Perovskite Solar Cells
Heyi Yang1, Tingting Xu1, Weijie Chen1*(陈炜杰), Yeyong Wu1, Xianming Guo5, Yunxiu Shen1, Chengqiang Ding3, Xining Chen1, Haiyang Chen1, Junyuan Ding1, Xiaoxiao Wu1, Guixiang Zeng6, Zhengbiao Zhang3,4*(张正彪), Yaowen Li1,2,3*(李耀文), Yongfang Li1,2,7,8
1Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor-optoelectronics Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China)
2Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University Suzhou 215123 (China)
3State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry,
Chemical Engineering and Materials Science, Soochow University Suzhou 215123 (China)
4State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123 (China)
5School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210008 (China)
6Kuang Yaming Honors School, Nanjing University Nanjing 210008 (China)
7Beijing National Laboratory for Molecular Sciences, Chinese Academy of Sciences Beijing 100190 (China)
8CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 (China)
Angew. Chem.Int. Ed. 2024, 63, e202316183
Abstract: To date, perovskite solar cells (pero-SCs) with doped 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (Spiro-OMeTAD) hole transporting layers (HTLs) have shown the highest recorded power conversion efficiencies (PCEs). However, their commercialization is still impeded by poor device stability owing to the hygroscopic lithium bis(trifluoromethanesulfonyl)imide and volatile 4-tert-butylpyridine dopants as well as time-consuming oxidation in air. In this study, we explored a series of single-component iodonium initiators with strong oxidability and different electron delocalization properties to precisely manipulate the oxidation states of Spiro-OMeTAD without air assistance, and the oxidation mechanism was clearly understood. Iodine (III) in the diphenyliodonium cation (IP+) can accept a single electron from Spiro-OMeTAD and forms Spiro-OMeTAD•+ owing to its strong oxidability. Moreover, because of the coordination of the strongly delocalized TFSI- with Spiro-OMeTAD•+ in a stable radical complex, the resulting hole mobility was 30 times higher than that of pristine Spiro-OMeTAD. In addition, the IP-TFSI initiator facilitated the growth of a homogeneous and pinhole-free Spiro-OMeTAD film. The pero-SCs based on this oxidizing HTL showed excellent efficiencies of 25.16 % (certified: 24.85 % for 0.062-cm2) and 20.71 % for a 15.03-cm2 module as well as remarkable overall stability.
链接：//onlinelibrary.wiley.com/doi/10.1002/anie.202316183
