[(C8H17)4N]4[SiW12O40] (TASiW‐12)‐Modified SnO2 Electron Transport Layer for Efficient and Stable Perovskite Solar Cells

• Published in: Solar RRL 2020-11, Vol.4 (11), p.n/a
• Main Authors: Shi, Zejiao, Zhang, Xin, Guo, Jia, Li, Xiaoguo, Weng, Zhenhua, Liu, Fengcai, Wu, Lixin, Ahmed, Irfan, Akram, Aftab, Javed, Sofia, Xing, Guichuan, Li, Fenghong, Zhan, Yiqiang, Zheng, Lirong
• Format: Article
• Language: English
• Subjects: dipoles; high-performance perovskites; hysteresis; perovskite solar cells
• ISSN: 2367-198X; 2367-198X
• DOI: 10.1002/solr.202000406

Recently, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has been developed to exceed 25%, and charge transport layer optimization is a promising strategy for further efficiency improvement in PSCs. Herein, a supramolecular complex [(C8H17)4N]4[SiW12O40] (TASiW‐12) is synthesized and its doped form in SnO2 (hereafter S‐SnO2) is used as a charge transport layer (electron transport layer, ETL). This study demonstrates that S‐SnO2 introduction is a practical and effective way to improve the bulk ETL and those of the ETL/perovskite interface. S‐SnO2 leads to improved band alignment, suppressed trap‐assisted charge recombination, and enhanced electron mobility. In addition, an enhanced open‐circuit voltage (Voc) of 1.16 V and an efficiency of 22.8% are successfully achieved in n–i–p planar PSCs. Meanwhile, S‐SnO2 acts as a crucial agent to reduce charge accumulation at the S‐SnO2/perovskite interface. The device possesses superior stability for 3072 h with only a 5.65% loss of the initial PCE. These results indicate that high‐efficiency PSCs can be easily attained by introducing a TASiW‐12‐doped ETL with integrated functions. Organic‐inorganic hybrid perovskite materials have emerged as promising photovoltaic candidates. Herein, a supramolecular complex [(C8H17)4N]4[SiW12O40] is synthesized and introduced into SnO2 to produce a mutifunctionalized electron transport layer (ETL). Suppressed trap state density and improved band alignment are attained in modified perovskite solar cells. Devices with [(C8H17)4N]4[SiW12O40] show a champion efficiency of 22.84% and stable performance under irradiation.