Surface and grain boundary defects in halide perovskite solar cells are highly detrimental,reducing efficiencies and stabilities.Widespread halide anion and organic cation defects usually aggravate ion diffusion and m...Surface and grain boundary defects in halide perovskite solar cells are highly detrimental,reducing efficiencies and stabilities.Widespread halide anion and organic cation defects usually aggravate ion diffusion and material degradation on the surfaces and at the grain boundaries of perovskite films.In this study,we employ an in-situ green method utilizing nontoxic cetyltrimethylammonium chloride(CTAC)and isopropanol(IPA)as anti-solvents to effectively passivate both surface and grain boundary defects in hybrid perovskites.Anion vacancies can be readily passivated by the chloride group due to its high electronegativity,and cation defects can be synchronously passivated by the more stable cetyltrimethylammonium group.The results show that the charge trap density was significantly reduced,while the carrier recombination lifetime was markedly extended.As a result,the power conversion efficiency of the cell can reach 23.4%with this in-situ green method.In addition,the device retains 85%of its original power conversion efficiency after 600 h of operation under illumination,showing that the stability of perovskite solar cells is improved with this in-situ passivation strategy.This work may provide a green and effective route to improve both the stability and efficiency of perovskite solar cells.展开更多
基金the National Key Research and Development Program of China(2016YFA0202400 and 2016YFA0202404)the National Natural Science Foundation of China(61904076 and U19A2089)+3 种基金the Natural Science Foundation of Guangdong Province(2020A1515010980 and 2019B1515120083)the Peacock Team Project funding from the Shenzhen Science and Technology Innovation Committee(KQTD2015033110182370)the Shenzhen Engineering R&D Center for Flexible Solar Cells Project funding from Shenzhen Development and Reform Committee(2019-126)the GuangdongHong Kong-Macao Joint Laboratory(2019B121205001)。
文摘Surface and grain boundary defects in halide perovskite solar cells are highly detrimental,reducing efficiencies and stabilities.Widespread halide anion and organic cation defects usually aggravate ion diffusion and material degradation on the surfaces and at the grain boundaries of perovskite films.In this study,we employ an in-situ green method utilizing nontoxic cetyltrimethylammonium chloride(CTAC)and isopropanol(IPA)as anti-solvents to effectively passivate both surface and grain boundary defects in hybrid perovskites.Anion vacancies can be readily passivated by the chloride group due to its high electronegativity,and cation defects can be synchronously passivated by the more stable cetyltrimethylammonium group.The results show that the charge trap density was significantly reduced,while the carrier recombination lifetime was markedly extended.As a result,the power conversion efficiency of the cell can reach 23.4%with this in-situ green method.In addition,the device retains 85%of its original power conversion efficiency after 600 h of operation under illumination,showing that the stability of perovskite solar cells is improved with this in-situ passivation strategy.This work may provide a green and effective route to improve both the stability and efficiency of perovskite solar cells.
