Luan Yigang, Yi Xiaohui, Mao Peng, Wei Yuanzhi, Zhuang Jing, Chen Ningli, Lin Tao, Li Cheng, Wang Jizheng
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
Semiconductor Photonics Research Center, OSED, Department of Physics, Jiujiang Research Institute, Xiamen University, Xiamen, Fujian 361005, P. R. China.
iScience. 2019 Jun 28;16:433-441. doi: 10.1016/j.isci.2019.06.004. Epub 2019 Jun 11.
An efficient electron transport layer (ETL) between the perovskite absorber and the cathode plays a crucial role in obtaining high-performance planar perovskite solar cells (PSCs). Here, we incorporate 2,2,2-trifluoroethanol (TFE) in the commonly used tin oxide (SnO) ETL, and it successfully improves the power conversation efficiency (PCE) and suppresses the hysteresis of the PSCs: the PCE is increased from 19.17% to 20.92%, and the hysteresis is largely reduced to be almost negligible. The origin of the enhancement is due to the improved electron mobility and optimized work function of the ETL, together with the reduced traps in the perovskite film. In addition, O plasma is employed to treat the surface of the TFE-incorporated SnO film, and the PCE is further increased to 21.68%. The concept here of incorporating organic small molecules in the ETL provides a strategy for enhancing the performance of the planar PSCs.
在钙钛矿吸收层与阴极之间的高效电子传输层（ETL）对于获得高性能平面钙钛矿太阳能电池（PSC）起着至关重要的作用。在此，我们将2,2,2-三氟乙醇（TFE）掺入常用的氧化锡（SnO）ETL中，成功提高了PSC的功率转换效率（PCE）并抑制了其滞后现象：PCE从19.17%提高到20.92%，滞后现象大幅减少至几乎可以忽略不计。性能增强的原因在于ETL的电子迁移率提高、功函数优化，以及钙钛矿薄膜中陷阱的减少。此外，采用氧等离子体处理掺入TFE的SnO薄膜表面，PCE进一步提高到21.68%。在ETL中掺入有机小分子这一概念为提高平面PSC的性能提供了一种策略。
