Uncovering the chemical structure dependence of ionic liquids as efficient and durable perovskite photovoltaic cell additives

• Ionic liquids (ILs) are known for their excellent environmental friendliness, stability, and solvation capabilities. More importantly, the tunability and configurability of its chemical structure shows great potential in promoting perovskite crystallization  and mitigating defects. Therefore, IL is favored in the field of perovskite solar cell (PSC) research. So far, most studies have focused on the effects of ILs with different anions on device performance modulation to explore the selection principles of ILs with suitable chemical structures in the field of PSCs, such as the regulation of the crystallization process and defect passivation. However, existing research lacks reports on the application of cations in the field of PSCs, and their specific role in the perovskite crystallization process and its impact on perovskite devices remain largely unexplored.

  
  

  Recently, Hu Hanlin of Shenzhen Vocational and Technical University, Li Gang of Hong Kong Polytechnic University, Zhu Quanyao of Wuhan University of Technology and others published the latest results on Nano Energy. The study used time-of-flight secondary ion mass spectrometry (TOF-SIMS) to verify 1-carboxymethyl-3- Differential distribution of carboxyl-functionalized cations and anions in perovskite films in methylimidazole chloride (C-EMIMCl), and systematically explored the IL additives of carboxyl-functionalized imidazole cations and traditional imidazole-based similar additives in perovskite films Various aspects of mineral device performance are affected, including chemical interactions, perovskite crystallization processes, film morphology, defect passivation and photovoltaic performance. The results show that the power conversion efficiency (PCE ) of the PSC champion device treated with C-EMIMCl is 24.21%, and at a relative humidity of 30% ± 5%, the corresponding PSCs can maintain 91.8% of the original PCE within 2000 h.

  
  

  The first author of the paper is doctoral candidate Wang Fei, and the corresponding authors are Associate Professor Hu Hanlin of Shenzhen Vocational and Technical University, Professor Li Gang of Hong Kong Polytechnic University, and Professor Zhu Quanyao of Wuhan University of Technology.

  
  

• 
• 
• 
• 

• Fei Wang, Dawei Duan, Yonggui Sun, Taomiao Wang, Guo Yang, Qiannan Li, Yongjun Li, Xiao Liang, Xianfang Zhou, Xiaokang Sun, Jing Ma, Jin Xiang, Jiajie Zhu, Quanyao Zhu, Kang Zhou, Haoran Lin, Yumeng Shi , Gang Li, Hanlin Hu, Nano Energy, 2024, 125, 109549.

  
  

  https://doi.org/10.1016/j.nanoen.2024.109549