Effective and reproducible method for preparing low defects perovskite film toward highly photoelectric properties with large fill factor by shaping capping layer

摘要

Recent development of perovskite solar cells have achieved great progress with power conversion efficiency reach to 22.1%. In this paper, we focus our attention on shaping perovskite capping layer (PCL) by adopting weak corrosive mixed anti-solvent to precisely control the capping layer thickness and crystallization. Ultra-dry gas flow was used for protecting perovskite film and inducing the formation of low defects perovskite crystal grain. The device performance is greatly enhanced after modifying the quality of CH3NH3PbI3 films with suitable PCL thickness and crystalline grain. The power conversion efficiency was boosted from 8.79% to 18.25% for the champion cell with the fill factor as high as 80.91% measured under conditions of AM 1.5G, 100 mW/cm(2). It is expected that this method can be used as a general approach for boosting the perovskite solar cell efficiency with different type of precursor material (MA,FA group and diverse combination with each other), such as MAPbX(3), FAPbX(3) and (FAPbl(3))(x) (MAPbBr(3))(1-x). Furthermore, the method exhibit good reproducibility and device stability due to high quality perovskite films and the device of the best one will be not deteriorated with the PCE maintaining over 80% after 60 days. (C) 2016 Published by Elsevier Ltd.