Template-Assisted Growth of High-Quality α-Phase FAPbI 3 Crystals in Perovskite Solar Cells Using Thiol-Functionalized MoS 2 Nanosheets

• Published in: ACS nano 2024-11, Vol.18 (44), p.30816-30828
• Main Authors: Yin, Yifan, Zhou, Yuchen, Fu, Shi, Lin, Yu-Chung, Zuo, Xianghao, Raut, Aniket, Zhang, Yugang, Tsai, Esther H R, Li, Mingxing, Lu, Fang, Zhou, Chenyu, Li, Tai-De, Kisslinger, Kim, Cotlet, Mircea, Nam, Chang-Yong, Rafailovich, Miriam H
• Format: Article
• Language: English
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.4c11268

Formamidinium lead iodide (FAPI) has gained attention for hybrid perovskite solar cell (PSC) applications due to its enhanced stability and narrow bandgap. However, a significant challenge remains in inducing and stabilizing the elusive perovskite "black phase"─photoactive cubic α-FAPI─as the relatively bulky FA cations tend to favor the thermodynamically stable nonphotoactive "yellow phase". In this study, we present a templated growth strategy employing thiol-functionalized MoS nanosheets as templates. By introduction of 3-mercaptopropionic acid (MPA)-functionalized MoS as a growth template, precise control over crystal formation was achieved, favoring the growth of high-quality α-FAPI films. These advanced templated films exhibited substantial improvements in charge transport properties, efficient light absorption, and enhanced charge extraction. As a result, the PSCs achieved a significantly enhanced power conversion efficiency (PCE) compared to the nontemplated control device, increasing from 20.6 to 22.5%. The MoS -incorporated device also demonstrated excellent shelf stability, maintaining 91% of the initial PCE even after 1600 h of storage without device encapsulation.