posted on 2024-01-10, 14:38authored byZhuojie Shi, Renjun Guo, Ran Luo, Xi Wang, Jianpeng Ma, Jiangang Feng, Xiuxiu Niu, Ezra Alvianto, Zhenrong Jia, Xiao Guo, Haoming Liang, Jinxi Chen, Zerui Li, Kun Sun, Xiongzhuo Jiang, Yuchen Wu, Peter Müller-Buschbaum, Wenping Hu, Yi Hou
Incorporating alkylammonium cations
atop the 3D perovskite enables
effective defect passivation and significantly enhances the power
conversion efficiency of perovskite solar cells. However, the diversity
and durability of this passivation strategy have been limited to the
ligand type and diffusion of ligands due to high reactivity. Here,
we designed bulky “T-shaped” conjugated carbazole alkylammonium
cations with inner π–π interaction and enlarged
steric hindrance to minimize ligand diffusion while maintaining passivation
effects. As verified by grazing incidence X-ray diffraction and transient
absorption spectra, these “T-shaped” passivators could
keep a stable intrinsic crystal phase on the perovskite surface after
thermal aging. Additionally, the devices utilizing these organic semiconductor-based
“T-shaped” ligands were relatively constant in series
resistance and introduced higher hole mobility than the PEAI. Finally,
the champion device using the “T-shaped” passivator
achieved a maximum device efficiency of 25.1% with improved operational
stability under 1 sun illumination.