Ionic Additive Engineering Toward High-Efficiency Perovskite Solar Cells with Reduced Grain Boundaries and Trap Density
Ionic Additive Engineering Toward High-Efficiency Perovskite Solar Cells with Reduced Grain Boundaries and Trap Density
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DOI：
10.1002/adfm.201801985
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发表时间：
2018-08-22
影响因子：
19
通讯作者：
Wang, Tao
中科院分区：
文献类型：
--
作者：
Cai, Feilong;Yan, Yu;Wang, Tao
有机-无机混合钙钛矿太阳能电池已成为产生可再生能源的有前途的光伏候选者之一。然而，存在于钙钛矿膜的本体或界面区域中的大量晶界和陷阱态限制了器件效率的进一步提高。本文介绍了一种在甲基碘化铵前体溶液中采用三甲基氯化铵的增材工程策略，以制备具有减少的晶界和陷阱密度的甲基碘化铅钙钛矿薄膜。这导致增加的电荷载流子扩散系数和扩散长度，如通过阻抗和电压衰减测量、强度调制光电压和光电流光谱所评估的。非辐射复合过程的比例显着降低，从而将这些钙钛矿太阳能电池的器件效率从19.1%提高到20.9%。
Organic-inorganic hybrid perovskite solar cells have emerged as one of the promising photovoltaic candidates to generate renewable energy. However, the large amounts of grain boundaries and trap states that exist in the bulk or interfacial regions of perovskite films limit further enhancement of device efficiency. Herein, an additive engineering strategy is introduced employing trimethylammonium chloride in the methylammonium iodide precursor solution to prepare methylammonium lead iodide perovskite films with reduced grain boundaries and trap densities. This leads to an increased charge carrier diffusion coefficient and diffusion length, as evaluated by impedance and voltage decay measurements, intensity-modulated photovoltage, and photocurrent spectroscopies. The proportion of nonradiative recombination processes is significantly reduced, consequently increasing device efficiency from 19.1% to 20.9% in these perovskite solar cells.