Effect of film morphologies on performance of perovskite solar cells and modules

Abstract

The quality of the perovskite films has an important effect on the performance of the perovskite solar cells. In this talk, we demonstrate the nucleation process plays a crucial role in the formation of the perovskite films with various morphologies. The low supersaturation results in films with porous morphologies because of the secondary nucleation. The high supersaturation results in films with compact morphologies due to the homogeneous nucleation. By adjusting the proportion of homogeneous nucleation and secondary nucleation based on an interface precipitation process induced by the antisolvent of n-hexane, we achieve perovskite films from porous morphologies to compact morphologies. The perovskite film with the three layers of structures has high light absorbance and large area of interface between perovskite and the hole transport materials, which result in high efficiency of the corresponding solar cells. In particular, surface of the carbon electrode is rather rough and the porous perovskite film enhances the interfacial contact area between carbon electrode and perovskite film. With the optimized perovskite films and carbon electrodes, we accomplish the fabrication of carbon based large-area and stable perovskite solar modules with the efficiency of over 13%. In addition, the morphology of TiO2 electron transport layer has also important influence on the efficiency of the solar cells. Based on the stable carbon-based perovskite solar cells, a kW-scale demonstration application of perovskite solar cells has been established.