Synthesis and properties of fluorine-containing polyhedral oligomeric silsesquioxanes (POSSs) modified hyperbranched white light-emitting materials for OLEDs

Polyhedral oligomericsilsesquioxanes (POSSs) are attractive in modifying the functionalities of traditional materials owing to their multifunctional cage-like structure. The fluorinated POSSs were introduced in the branches of polyfluorene (PF)-based hyperbranched white-emitting polymers with spiro[3.3]heptane-2,6-dispirofluorene (SDF) as the branching center. The structure-activity relationship of the molecules was explored to modify the white-light performance by adjusting the feeding ratios of POSSs and the distance between the main chain. The results indicated that the introduced fluorinated POSSs maintained amorphous morphology of the film, and improved thermal stabilities and hydrophobicity of the polymers. Consequently, the single light-emitting layered devices based on the polymers realized white light-emission and exhibited good electroluminescent (EL) performance with high color saturation, which are attractive application prospects for white polymer light-emitting diodes.