High efficiency and long-term stability are prerequisites for the commercialization of perovskite solar cells (PSCs). However, insufficient and uneven doping of the hole transport layer (HTL ) still limits efficiency improvement, and the inherent instability of HTL caused by ion migration and accumulation is difficult to solve through external packaging.
Tang Weihua, Zhang Jinbao and others from Xiamen University demonstrated that adding conjugated phosphonic acid (CPA) to Spiro-OMeTAD benchmark HTL can greatly enhance its optoelectronic performance and reliability, thereby improving device efficiency and intrinsic stability. Indole[3,2-b]carbazole-5,11-diylbis(butane-4,1-diyl)bis(phosphonic acid) (BCZ) has an optimal dibasic acid structure designed to promote Morphological uniformity and mitigated ion migration across the perovskite/HTL and HTL/Ag interfaces, enabling superior charge conductivity, enhanced ion immobilization, and superior film stability.
The significant improvement in interfacial charge collection enables the BCZ-based nip PSC to have an efficiency of 24.51%. BCZ-based devices maintain 90% of their initial efficiency after 3,000 hours of air storage. This CPA-modified HTL exhibits high versatility in flexible and large-area devices. This work provides a facile and effective molecular strategy to enhance charge transport layers and paves the way for further development of robust organic HTLs for efficient and intrinsically stable optoelectronic devices.
X. Li, W. Wang, K. Wei, J. Deng, P. Huang, P. Dong, X. Cai, L. Yang, W. Tang, J. Zhang, Conjugated Phosphonic Acids Enable Robust Hole Transport Layers for Efficient and Intrinsically Stable Perovskite Solar Cells. Adv. Mater. 2023, 2308969.
https://doi.org/10.1002/adma.202308969
https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202308969
E-mail: info@chemborun.com
Tel: +86-574-87178138 
No. 1558, Jiangnan Road,, Ningbo, Zhejiang, China (Mainland)/31
