Optimisation of polyfluorenes for light emitting applications

The properties of polyfluorenes for use in luminescent devices have been improved by a variety of approaches Their conjugation length may be extended by using more planar indenofluorene units. Formation of long wavelength emitting aggregates is suppressed by attachment of bulky dendron groups to give stable blue emission. The emission colour can be tuned across the visible spectrum by incorporation of perylene dye units on the main chain or as substituents. Rod-coil copolymers have been made in order to achieve control of the supramolecular order. Polyfluorenone prepared by a precursor route shows improved electron injection and transport properties. (C) 2001 Elsevier Science B.V. All rights reserved.