Semi-perfluoroalkyl polyfluorene with varying fluorine content: Synthesis and photophysical properties

Deposition of multilayer organic electronic devices by solution processing often requires clever material design to avoid intermixing of the various layers. The use of orthogonal solvents for multilayer processing is a simple and effective method to solve this problem. However, the introduction of fluorous substituents to materials normally functionalised with aliphatic side chains has been shown to affect the device performance of these materials. In this study, a series of 9,9-disubstituted polyfluorenes containing varying ratios of semi-perfluoroalkyl to alkyl side chains have been synthesised and characterised. The effect of the semi-perfluoroalkyl chains on photophysical, electrochemical and thermal properties of the polymers was examined. The results indicate that the semi-perfluoroalkyl chains have varying influence on these properties and this is reflected in the previously reported electroluminescent device performances.