title: Solvent annealing of PbI2for the high-quality crystallization of perovskite films for solar cells with efficiencies exceeding 18.
abstract: While most work carried out to date has focused on the solvent annealing of perovskite, in the present work, we focused on the solvent annealing of lead iodide. Based on the two-step spin-coating method, we designed a screening method to search for an effective solvent annealing process for PbI2. PbI2films were annealed in diverse solvent atmospheres, including DMF, DMSO, acetone, and isopropanol (IPA). We found that the solvent annealing of PbI2in the DMF, acetone, and IPA atmospheres resulted in dense PbI2films, which impeded the complete conversion of PbI2to CH3NH3PbI3. Surprisingly, employing the DMSO solvent annealing process for PbI2led to porous PbI2, which facilitated the complete conversion of PbI2to perovskite with larger grain sizes. Solar cells fabricated using the DMSO solvent annealing process exhibited the best efficiency of 18.5%, with a fill factor of 76.5%. This unique solvent annealing method presents a new way of controlling the perovskite film quality for highly efficient solar cells.
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, China. shibinli@uestc.edu.cn zhichen@engr.uky.edu.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, China. shibinli@uestc.edu.cn zhichen@engr.uky.edu.
authors.forename: Shibin
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, China. shibinli@uestc.edu.cn zhichen@engr.uky.edu.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, China. shibinli@uestc.edu.cn zhichen@engr.uky.edu.
authors.forename: Detao
authors.initials: D
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, China. shibinli@uestc.edu.cn zhichen@engr.uky.edu.
authors.forename: Xiangling
authors.initials: X
authors.lastname: Gu
authors.affiliation: Department of Electrical & Computer Engineering, and Center for Nanoscale Science & Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
authors.forename: Hojjatollah
authors.initials: H
authors.lastname: Sarvari
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, China. shibinli@uestc.edu.cn zhichen@engr.uky.edu and Department of Electrical & Computer Engineering, and Center for Nanoscale Science & Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
authors.forename: Zongbiao
authors.initials: Z
authors.lastname: Ye
authors.affiliation: Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, UK.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.affiliation: Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, China. shibinli@uestc.edu.cn zhichen@engr.uky.edu and Department of Electrical & Computer Engineering, and Center for Nanoscale Science & Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
authors.forename: Zhi David
authors.initials: ZD
authors.lastname: Chen