Wei Mingyang, Xiao Ke, Walters Grant, Lin Renxing, Zhao Yongbiao, Saidaminov Makhsud I, Todorović Petar, Johnston Andrew, Huang Ziru, Chen Haijie, Li Aidong, Zhu Jia, Yang Zhenyu, Wang Ya-Kun, Proppe Andrew H, Kelley Shana O, Hou Yi, Voznyy Oleksandr, Tan Hairen, Sargent Edward H
Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, M5S 3G4, Canada.
National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China.
Adv Mater. 2020 Mar;32(12):e1907058. doi: 10.1002/adma.201907058. Epub 2020 Feb 7.
The development of narrow-bandgap (E ≈ 1.2 eV) mixed tin-lead (Sn-Pb) halide perovskites enables all-perovskite tandem solar cells. Whereas pure-lead halide perovskite solar cells (PSCs) have advanced simultaneously in efficiency and stability, achieving this crucial combination remains a challenge in Sn-Pb PSCs. Here, Sn-Pb perovskite grains are anchored with ultrathin layered perovskites to overcome the efficiency-stability tradeoff. Defect passivation is achieved both on the perovskite film surface and at grain boundaries, an approach implemented by directly introducing phenethylammonium ligands in the antisolvent. This improves device operational stability and also avoids the excess formation of layered perovskites that would otherwise hinder charge transport. Sn-Pb PSCs with fill factors of 79% and a certified power conversion efficiency (PCE) of 18.95% are reported-among the highest for Sn-Pb PSCs. Using this approach, a 200-fold enhancement in device operating lifetime is achieved relative to the nonpassivated Sn-Pb PSCs under full AM1.5G illumination, and a 200 h diurnal operating time without efficiency drop is achieved under filtered AM1.5G illumination.
窄带隙（E≈1.2 eV）的混合锡铅（Sn-Pb）卤化物钙钛矿的发展推动了全钙钛矿串联太阳能电池的发展。尽管纯铅卤化物钙钛矿太阳能电池（PSC）在效率和稳定性方面同时取得了进展，但在Sn-Pb PSC中实现这种关键组合仍然是一个挑战。在这里，Sn-Pb钙钛矿晶粒通过超薄层状钙钛矿进行锚固，以克服效率-稳定性的权衡。在钙钛矿薄膜表面和晶界处都实现了缺陷钝化，这是通过在反溶剂中直接引入苯乙铵配体来实现的一种方法。这提高了器件的运行稳定性，还避免了层状钙钛矿的过度形成，否则会阻碍电荷传输。报道了填充因子为79%、认证功率转换效率（PCE）为18.95%的Sn-Pb PSC，这是Sn-Pb PSC中最高的之一。使用这种方法，相对于未钝化的Sn-Pb PSC，在全AM1.5G光照下器件运行寿命提高了200倍，在过滤后的AM1.5G光照下实现了200小时的日间运行时间且效率无下降。
