Two-step ultrasonic spray deposition of CH3NH3PbI3 for efficient and large-area perovskite solar cell

A two-step ultrasonic spray method has been developed to fabricate centimeter-scale uniform and smooth perovskite CH3NH3PbI3 films for efficient and large-area solar cells. Aside from the advantages in larger area and higher smoothness, the perovskite films deposited by this method showed better crystallinity, lower non-radiative recombination and more efficient interfacial charge extraction properties. Through systematical optimizations, an efficient mesoscopic solar cell was finally achieved with efficiency of 16.03%. Furthermore, large-area (1 x 1 cm(2)) cell was also fabricated, giving an efficiency of 13.09%. This work demonstrates that the two-step spray method can be a promising alternative to deposit high-quality and large-area perovskite absorbers to afford high cell performance. (C) 2016 Published by Elsevier Ltd.