Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , P. R. China.
Beijing National Laboratory for Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , P. R. China.
ACS Appl Mater Interfaces. 2019 Sep 18;11(37):33825-33834. doi: 10.1021/acsami.9b09238. Epub 2019 Sep 4.
Tin dioxide (SnO) has been widely applied as an electron transport layer (ETL) for the n-i-p-type perovskite solar cells (Pero-SCs). However, the existence of defects at the surface of SnO and the hysteresis behavior of the devices with SnO ETL limit its application in the Pero-SCs. In this study, a fullerene derivative pyrrolidinofullerene C-substituted phenol (NPC-OH) was synthesized and applied to modify the SnO ETL in Pero-SCs for the first time. The systematic and comparative characterizations demonstrated that, after the introduction of an NPC-OH modification layer on the SnO ETL, the perovskite films in the corresponding device showed enlarged grain size and these devices presented enhanced electron transport and decreased charge recombination velocity. Besides, the NPC-OH layer could significantly reduce the trap-state density in the perovskite film. As a result, a champion power conversion efficiency (PCE) of 21.39% was achieved for the SnO/NPC-OH-based Pero-SCs, with suppressed hysteresis and improved stability, while the control devices with pristine SnO ETL showed a lower PCE of 19.04%.
二氧化锡（SnO）已被广泛应用于 n-i-p 型钙钛矿太阳能电池（Pero-SCs）的电子传输层（ETL）。然而，SnO 表面存在的缺陷以及具有 SnO ETL 的器件的滞后行为限制了其在 Pero-SCs 中的应用。在本研究中，首次合成了富勒烯衍生物吡咯啉 fullerene C 取代苯酚（NPC-OH）并将其应用于修饰 Pero-SCs 中的 SnO ETL。系统和比较的特性表明，在 SnO ETL 上引入 NPC-OH 修饰层后，相应器件中的钙钛矿薄膜显示出更大的晶粒尺寸，这些器件表现出增强的电子传输和降低的电荷复合速率。此外，NPC-OH 层可显著降低钙钛矿薄膜中的陷阱态密度。结果，基于 SnO/NPC-OH 的 Pero-SCs 获得了 21.39%的卓越功率转换效率（PCE），同时抑制了滞后现象并提高了稳定性，而具有原始 SnO ETL 的对照器件的 PCE 则较低，为 19.04%。
