摘要
目前钙钛矿太阳能电池多采用反溶剂成膜法制备钙钛矿吸收层,其优点是工艺简便、成本低廉.但是反溶剂法是一种快速结晶的制备方法,容易在钙钛矿薄膜晶粒的晶界和表面形成大量的缺陷,导致钙钛矿太阳能电池器件效率和稳定性的下降.虽然通过钙钛矿成膜之后再沉积钝化材料的后处理法可以钝化钙钛矿薄膜表面的缺陷,但是这种后处理法无法有效钝化晶粒界面处的缺陷.同时,由于目前多采用氯苯和甲苯等有毒溶剂作为反溶剂,制备过程产生的有毒污染较为严重.为了解决上述问题,本文将无毒的十六烷基三甲基氯化铵作为钝化剂直接加入无毒的异丙醇中作为绿色反溶剂,可以在钙钛矿晶体生长和成膜的过程中原位钝化晶粒的界面和表面的缺陷.通过这种原位钝化的方法,可以将钙钛矿太阳能电池器件的效率由20.3%提升至23.4%,并且稳定性也得到了明显提高.
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.
作者
刘畅
黄磊
周贤勇
王行柱
姚建曦
刘治科
刘生忠
马万里
徐保民
Chang Liu;Lei Huang;Xianyong Zhou;Xingzhu Wang;Jianxi Yao;Zhike Liu;Shengzhong Frank Liu;Wanli Ma;Baomin Xu(Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Shenzhen 518055,China;Department of Materials Science and Engineering and Shenzhen Engineering Research and Development Center for Flexible Solar Cells,Southern University of Science and Technology,Shenzhen 518055,China;Key Laboratory of Energy Conversion and Storage Technologies(Southern University of Science and Technology),Ministry of Education,Shenzhen 518055,China;Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices,Southern University of Science and Technology,Shenzhen 518055,China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China;Key Laboratory of Applied Surface and Colloid Chemistry(Ministry of Education),Shaanxi Key Laboratory for Advanced Energy Devices,Shaanxi Engineering Laborartory for Advanced Energy Technology,School of Materials Science and Engineering,Shaanxi Normal University,Xi’an 710119,China;Institute of Functional Nano&Soft Materials,Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices,Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,Soochow University,Suzhou 215123,China)
基金
the National Key Research and Development Program of China(2016YFA0202400 and 2016YFA0202404)
the National Natural Science Foundation of China(61904076 and U19A2089)
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)。
