Unexpected surface interactions between fluorocarbons and hybrid organic inorganic perovskites evidenced by PM-IRRAS and their application towards tuning the surface potential

The chemical nature and orientation of fluorinated monolayers on CH3NH3PbI3 perovskites is probed through XPS and PM-IRRAS measurements. We show that even perfluoro-n-alkanes interact with the HOIP surface to form stable monolayers with well-defined orientation and that the surface potential of CH3NH3PbI3 can be easily tuned over a 150 mV range using various fluorinated porphyrin monolayers.