Gharibzadeh Saba, Valduga de Almeida Camargo Franco, Roldán-Carmona Cristina, Gschwend Grégoire Clément, Pascual Jorge, Tena-Zaera Ramón, Cerullo Giulio, Grancini Giulia, Nazeeruddin Mohammad Khaja
Group for Molecular Engineering of Functional Materials, Ecole Polytechnique Fédérale Lausanne Valais Wallis, Sion, CH-1951, Switzerland.
Department of Physics, Tarbiat Modares University, P.O. Box 14115-175, Tehran, 14117-13116, Iran.
Adv Mater. 2018 Aug 23:e1801496. doi: 10.1002/adma.201801496.
In this work, solar cells based on methylammonium lead iodide (MAPbI ) doped in solution with C fullerene in a mesoporous as well as planar electron-transporting layer (ETL)-free architecture are realized, showcasing in the latter case a record efficiency of 15.7% and an improved open-circuit voltage (V ). Contrary to the bulk heterojunction previously reported, the C molecules do not phase segregate and they are rather finely dispersed in the perovskite film, possibly infiltrating at the grain boundaries, while assisting the growth of a highly uniform perovskite layer. By means of time-resolved femtosecond-to-nanosecond optical spectroscopy, with an extended spectral coverage, it is observed that electrons photogenerated in the perovskite are transferred to C with a time constant of 20 ps. Despite being captured by C , electrons are not deeply trapped and can potentially bounce back into the perovskite, as suggested by the high fill factor and enhanced V of the MAPbI :C solar cells, especially in the case of the ETL-free device configuration.
在这项工作中，实现了基于在溶液中掺杂C富勒烯的甲基铵碘化铅（MAPbI）的太阳能电池，其采用介孔以及无平面电子传输层（ETL）结构，在后一种情况下展示出15.7%的创纪录效率和改善的开路电压（V）。与先前报道的体异质结相反，C分子不会发生相分离，而是相当精细地分散在钙钛矿薄膜中，可能渗透到晶界处，同时有助于生长高度均匀的钙钛矿层。通过具有扩展光谱覆盖范围的时间分辨飞秒至纳秒光谱学观察到，在钙钛矿中光生的电子以20 ps的时间常数转移到C。尽管被C捕获，但电子不会被深度捕获，并且可能反弹回钙钛矿中，这由MAPbI:C太阳能电池的高填充因子和增强的V所表明，特别是在无ETL器件配置的情况下。
