Antiphase Boundaries Regulate Phase Stability and Performance in DMA <sup>+</sup> ‐Assisted CsPbI <sub>3</sub> ‐Based Perovskites
Abstract
ABSTRACT CsPbI 3 ‐based perovskites are promising absorbers for tandem solar cells owing to their optimal bandgap (∼1.7 eV). However, the phase transition from photoactive γ‐CsPbI 3 to non‐photoactive δ‐CsPbI 3 remains a major obstacle and is strongly governed by microstructural defects formed during film growth. Among these, Ruddlesden–Popper antiphase boundaries (RP‐APBs) are particularly prevalent and exhibit competing effects, relieving lattice strain while simultaneously facilitating moisture penetration, ion migration, and nonradiative recombination. Here, we systematically regulate RP‐APB defects in γ‐phase CsPbI 3 thin films and elucidate their decisive influence on both phase stability and optoelectronic performance. A compositional strategy based on PbI 2 excess effectively reduces RP‐APB density but induces edge‐sharing [PbI 6 ] 4− motifs that nucleate the δ phase. In contrast, a dimethylammonium (DMA + )‐assisted phase‐engineering strategy forms β‐(DMA,Cs)PbI 3 , which intrinsically suppresses RP‐APB formation while preserving the photoactive perovskite framework. As a result, RP‐APB‐free β‐phase films exhibit prolonged carrier lifetimes, strongly suppressed nonradiative recombination, and the lowest apparent trap densities, enabling a champion power conversion efficiency of 20.23% together with markedly enhanced operational, thermal, and ambient‐air stability. This work demonstrates that regulating crystalline defects, exemplified by RP‐APBs, plays a critical role in achieving both stable and efficient perovskite solar cells.
Article Details
Authors (16)
Zhi‐Wen Yin
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China
Nan Li
Yang Jiang
Department of Chemistry
Xin‐Jun Yang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China
Ji‐Hong Zheng
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China
Qi‐Bo Yuan
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China
Yu‐Chen Wang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China
Yu‐Song Xiao
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China
Jing‐Yi Sun
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China
Yan‐Bing Chen
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China
Wanchun Xiang
Key Laboratory of Applied Surface and Colloid Chemistry National Ministry of Education Shaanxi Key Laboratory For Advanced Energy Devices Shaanxi Engineering Lab For Advanced Energy Technology School of Materials Science and Engineering Shaanxi Normal University Xi'an P. R. China
Yu Li
Yi‐Bing Cheng
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 P.R. China
Gustaaf Van Tendeloo
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, China.
Wei Li
Zhi‐Yi Hu
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & Nanostructure Research Centre (NRC) Wuhan University of Technology Wuhan China