2D Dion–Jacobson CsPbI3 with Enhanced Interlayer Coupling for Stable and Efficient Photovoltaics. Issue 31 (13th September 2022)

• Record Type: Journal Article
• Authors: Lei, Yutian; Peng, Guoqiang; Wang, Haoxu; Wang, Gang; Yang, Siwei; Wang, Qian; Li, ZhenHua; Jin, Zhiwen
• Is Part Of: Advanced materials interfaces. Volume 9:Issue 31(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-13
• Subjects: 2D inorganic perovskite -- Dion–Jacobson -- efficiency and stability -- layer coupling -- Ruddlesden–Popper; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202201501
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: Inorganic 2D layered CsPbI3 is awaiting to overcome the phase instability of traditional 3D components. However, the most reported Ruddlesden–Popper (RP) phase 2D CsPbI3 leads to larger interlayer distance and weaker interlayer coupling since the existence of the van der Waals gap, which deteriorates the performance of the device and makes the improvement of stability unsatisfactory. Herein, this work resorts ethylenediamine cations (EDA 2+ ) to construct a series of Dion–Jacobson (DJ) phase 2D CsPbI3 as (EDA)Cs n −1 Pb n I3 n +1 with van der Waals gap eliminated. Combining simulation calculations and experiments, it is found that the (EDA)Cs n −1 Pb n I3 n +1 has enhanced intermolecular forces to overcome the problem of insufficient crystallization power caused by large steric hindrance in the film assembly process compared to phenethylammonium‐based RP phase analogues. In addition, profit from the reduced interlayer distance and stronger coupling, the rigidity of the structure is increased, and the annoying non‐radiative recombination caused by structural fluctuations is alleviated. As a result, the 2D layered DJ phase CsPbI3 ‐based solar cells deliver eminent performance than RP phase analogues, especially the 2D (EDA)(Cs)4 Pb5 I16 ( n = 5) device exhibits a record PCE of 10.43% in this work, and significantly enhanced stability. Abstract : This work mainly constructs 2D Dion–Jacobson phase CsPbI3 by introducing EDA 2+, which eliminates van der Waals gap, reduces the interlayer spacing, and substantially enhances the coupling effect. Meanwhile, the strong intermolecular interaction modulates the crystallization kinetics. As a result, the 2D (EDA)(Cs)4 Pb5 I16 device exhibits a record power conversion efficiency of 10.43%, and significantly enhanced stability.