Multi-functional organic molecules for surface passivation of perovskite

The stability of perovskite is a bottleneck for the application of perovskite solar cells. Herein, 4-ethylamine Phenylphosphate disodium salt (EAPP) was explored as a functional surface ligand to passivate perovskite surface. As the addition of 1 mol% of EAPP, the degradation of the film in high humidity condition was effectively reduced. Solar cells based on EAPP doped perovskite film show merely slight decrease of its initial efficiency in high humidity condition, whereas the control device show catastrophic decrease. Apart from as a passivating molecule to protect perovskite from contacting with water, EAPP show function as a reducing reagent to bond with hydrogen iodide formed in perovskite decomposition. (C) 2017 Elsevier B.V. All rights reserved.