Cheng Gong: Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education), Chongqing University, Chongqing, 400044, People's Republic of China.
Cong Zhang: Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education), Chongqing University, Chongqing, 400044, People's Republic of China.
Qixin Zhuang: Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education), Chongqing University, Chongqing, 400044, People's Republic of China.
Haiyun Li: Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education), Chongqing University, Chongqing, 400044, People's Republic of China.
Hua Yang: Institute of High Energy Physics, Chinese Academy of Sciences (CAS), Beijing, 100049, People's Republic of China.
Jiangzhao Chen: Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education), Chongqing University, Chongqing, 400044, People's Republic of China. jiangzhaochen@cqu.edu.cn.
Zhigang Zang: Key Laboratory of Optoelectronic Technology and Systems (Ministry of Education), Chongqing University, Chongqing, 400044, People's Republic of China. zangzg@cqu.edu.cn.
The interfacial defects and energy barrier are main reasons for interfacial nonradiative recombination. In addition, poor Perovskite crystallization and incomplete conversion of PbI to Perovskite restrict further enhancement of the photovoltaic performance of the devices using sequential deposition. Herein, a buried interface stabilization strategy that relies on the synergy of fluorine (F) and sulfonyl (S=O) functional groups is proposed. A series of potassium salts containing halide and non-halogen anions are employed to modify SnO/Perovskite buried interface. Multiple chemical bonds including hydrogen bond, coordination bond and ionic bond are realized, which strengthens interfacial contact and defect passivation effect. The chemical interaction between modification molecules and Perovskite along with SnO heightens incessantly as the number of S=O and F augments. The chemical interaction strength between modifiers and Perovskite as well as SnO gradually increases with the increase in the number of S=O and F. The defect passivation effect is positively correlated with the chemical interaction strength. The crystallization kinetics is regulated through the compromise between chemical interaction strength and wettability of substrates. Compared with Cl, all non-halogen anions perform better in crystallization optimization, energy band regulation and defect passivation. The device with potassium bis (fluorosulfonyl) imide achieves a tempting efficiency of 24.17%.
