NaHCO3‐induced porous PbI2 enabling efficient and stable perovskite solar cells
Yitian Du,
Ying Wang,
Jihuai Wu,
Qi Chen,
Chunyan Deng,
Ran Ji,
Liuxue Sun,
Lina Tan,
Xia Chen,
Yiming Xie,
Yunfang Huang,
Yana Vaynzof,
Peng Gao,
Weihai Sun,
Zhang Lan
Affiliations
Yitian Du
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Ying Wang
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Jihuai Wu
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Qi Chen
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Chunyan Deng
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Ran Ji
Integrated Centre for Applied Physics and Photonic Materials Technical University of Dresden Dresden Germany
Liuxue Sun
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Lina Tan
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Xia Chen
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Yiming Xie
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Yunfang Huang
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Yana Vaynzof
Integrated Centre for Applied Physics and Photonic Materials Technical University of Dresden Dresden Germany
Peng Gao
Chinese Academy of Science Xiamen Institute of Rare Earth Mater Xiamen the People's Republic of China
Weihai Sun
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Zhang Lan
Engineering Research Center of Environment‐Friendly Functional Materials, Ministry of Education Institute of Materials Physical Chemistry, Huaqiao University Xiamen the People's Republic of China
Abstract Driven by their many unique features, perovskite solar cells (PSCs) have become one of the most promising candidates in the photovoltaic field. Two‐step preparation of perovskite film is advantageous for its higher stability and reproducibility compared to the one‐step method, which is more suitable for practical application. However, the incomplete conversion of the dense lead iodide (PbI2) layer during the sequential spin‐coating of formamidinium/methylammonium (FA+/MA+) organic amine salts severely affect the performance of PSCs. Herein, sodium bicarbonate (NaHCO3) is used to induce the formation of porous PbI2, which facilitates the penetration of the FA+/MA+ ions and the formation of a perovskite film with high crystallinity and large grain microstructure. Meanwhile, the introduction of Na+ not only improves the energetic alignment of the PSC, but also increases the conductivity via p‐doping. As a result, the optimized NaHCO3‐modified PSC achieves a champion power conversion efficiency of 24.0% with suppressed hysteresis. Moreover, the significant reduction in defect density and ion migration as well as a mild alkaline environment enhance the stability of device. The unencapsulated NaHCO3‐modified PSCs maintain over 90% of their original efficiency upon storage in ambient air (30%–40% relative humidity) for 2160 h. We have demonstrated an ingenious strategy for controlling the quality of perovskite and improving the performance of device by low‐temperature foaming of simple inorganic molecules of NaHCO3.