Molecular Ferroelectrics‐Driven High‐Performance Perovskite Solar Cells

• Published in: Angewandte Chemie International Edition Vol. 59; no. 45; pp. 19974 - 19982
• Main Authors: Xu, Xiao‐Li, Xiao, Ling‐Bo, Zhao, Jie, Pan, Bing‐Kun, Li, Jun, Liao, Wei‐Qiang, Xiong, Ren‐Gen, Zou, Gui‐Fu
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 02.11.2020
• Edition: International ed. in English
• Subjects: built-in electric fields; defect passivation; Electric fields; Electron recombination; Energy conversion efficiency; Energy dissipation; Energy loss; Ferroelectric materials; Ferroelectricity; molecular ferroelectrics; Molecular structure; Perovskites; Photoluminescence; Photons; Photovoltaic cells; Photovoltaics; poling; Recombination; Separation; Solar cells
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202008494

The nonradiative recombination of electrons and holes has been identified as the main cause of energy loss in hybrid organic–inorganic perovskite solar cells (PSCs). Sufficient built‐in field and defect passivation can facilitate effective separation of electron–hole pairs to address the crucial issues. For the first time, we introduce a homochiral molecular ferroelectric into a PSC to enlarge the built‐in electric field of the perovskite film, thereby facilitating effective charge separation and transportation. As a consequence of similarities in ionic structure, the molecular ferroelectric component of the PSC passivates the defects in the active perovskite layers, thereby inducing an approximately eightfold enhancement in photoluminescence intensity and reducing electron trap‐state density. The photovoltaic molecular ferroelectric PSCs achieve a power conversion efficiency as high as 21.78 %. A homochiral molecular ferroelectric was incorporated into a perovskite film to enlarge the built‐in electric field of the perovskite solar cell (PSC), thereby facilitating charge separation and transportation. The molecular ferroelectric component of the PSC passivates the defects in the perovskite active layers to induce an approximately eightfold enhancement in photoluminescence intensity and a reduction in electron trap‐state density.