Pseudo‐Arch Bridge‐Inspired Stress Modulation at Buried Interface for Stable High‐Efficiency Perovskite Solar Cells
Abstract
Abstract Thermal instability remains a key barrier to the commercialization of perovskite solar cells (PSCs), largely due to severe thermomechanical mismatch at the buried interface between the perovskite and transport layers. This mismatch induces interfacial strain, triggering deep‐level defects, ion migration, and phase segregation that severely impair device stability. Here, a thermomechanical stress engineering strategy is introduced via rational molecular interface design. Specifically, a novel molecule, 4‐(5,6‐difluoro‐2‐(pyridin‐2‐yl)‐1H‐benzo[d]imidazol‐1‐yl)butan‐1‐ammonium iodide (FBI‐PyAI) is synthesized, that anchors at the TiO 2 /perovskite interface likely in a unique “molecular bridge” configuration. This soft interface yields an extremely low modulus and significantly reduces the interfacial stress energy from 0.554 to 0.178 eV, thereby suppressing defect formation and minimizing phase segregation. Meanwhile, the functional groups in FBI‐PyAI passivate defects and induce vertically oriented perovskite crystallization, forming compact films with fewer voids and improved structural uniformity. As a result, the modified devices achieve exceptional thermal stability, which maintains 88% of initial efficiency after 50 thermal cycles (−15 to 65 °C). Moreover, the modified PSC delivers a competitive efficiency of 25.01% and outstanding photostability (95% retention after 800 h illumination under ISOS‐L‐1 protocol). This work offers mechanistic insight into interfacial stress modulation and underscores its importance for thermally stable PSCs.
Article Details
Authors (18)
Jie Gao
State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials
Jihong Wu
Dong Wei
Naize Chen
College of Physics and Energy Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, Strait Institute of Flexible Electronics (SIFE, Future Technologies) Fujian Key Laboratory of Flexible Electronics Fujian Normal University Fuzhou Fujian 350117 China
Pengxiang Wang
State Key Laboratory of Flexible Electronics (LoFE) Institute of Advanced Materials (IAM)，School of Chemistry and Life Science Nanjing University of Posts and Telecommunications 9 Wenyuan Road Nanjing 210023 P.R. China
Xiaozhen Huang
Xiafeng He
Strait Institute of Flexible Electronics (SIFE, Future Technologies), Fujian Key Laboratory of Flexible Electronics, College of Physics and Energy, Strait Laboratory of Flexible Electronics (SLoFE) Fujian Normal University Fuzhou Fujian 350117 P.R. China
Shidong Cai
Strait Institute of Flexible Electronics (SIFE, Future Technologies), Fujian Key Laboratory of Flexible Electronics, College of Physics and Energy, Strait Laboratory of Flexible Electronics (SLoFE) Fujian Normal University Fuzhou Fujian 350117 P.R. China
Xuran Wang
Yidi Zhao
Xiaodan Li
Guilin Chen
Zhiling Luo
Hongxiang Li
College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering
Mingwei An
Strait Institute of Flexible Electronics (SIFE, Future Technologies), Fujian Key Laboratory of Flexible Electronics, College of Physics and Energy, Strait Laboratory of Flexible Electronics (SLoFE) Fujian Normal University Fuzhou Fujian 350117 P.R. China
Wei Huang
Yang Wang
Dandan Song
State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering