Ruthenium Complex Optimized Contact Interfaces of NiO X Nanocrystals for Efficient and Stable Perovskite Solar Cells

• Published in: Solar RRL 2024-02, Vol.8 (4), p.n/a
• Main Authors: Luo, Gan, Zhang, Yuxi, Zhu, Qinglong, An, Ziqi, Lv, Pin, Chen, Jiahui, Zhu, Yanqing, Hu, Min, Li, Wangnan, Cao, Kun, Ku, Zhiliang, Huang, Wenchao, Cheng, Yi‐Bing, Lu, Jianfeng
• Format: Article
• Language: English
• Subjects: interface modification; nickel oxide nanoparticles; perovskite solar cells; photostability
• ISSN: 2367-198X; 2367-198X
• DOI: 10.1002/solr.202300890

Nickel oxide (NiO X ) is a desirable hole‐transporting material for perovskite solar cells owing to their merits of low‐cost, stable, and readily scalable. However, the NiO X |perovskite interface suffers from serious recombination and poor photostability because of the interfacial redox reactions. Herein, NiO X nanoparticles with tunable size have been synthesized at low temperatures by controlling the reactivity of the hydrolysis reaction. A self‐assembled monolayer composed of a ruthenium complex, i.e., C106, is then introduced to optimize the interfacial properties. The C106 molecule chemically bonds to NiO X via carboxyl acid group, which passivates the surface defects of NiO X and suppresses the negative redox reaction at the interface. The modification leads to an improvement in perovskite film morphology, crystallization, and band alignment. As a result, the efficiency of solar cells has been improved from 18.1% to 20.5%. More importantly, the modified solar cells retain >80% of their initial performance after continuous operation under 100 mW cm−2 irradiation for 800 h, which is much enhanced than the unmodified devices. By controlling the reactivity of the hydrolysis reaction, NiO X nanoparticles with tunable size are synthesized at low temperatures. A self‐assembled monolayer composed by C106 dye has been introduced to improve the efficiency and stability of perovskite solar cells (PSCs). As a result, an efficiency of 20.5% along with ≈800 h continuous operational stability is achieved.